SYLLABUS

TOPICS/CONTENTS/
NOTES OBJECTIVES
1. MEASUREMENTS AND
UNITS
(a) Length, area and
volume: Metre rule,
Venier calipers
Micrometer
Screw-guage,
measuring cylinder
(b) Mass
(i) unit of mass
(ii) use of simple
beam balance
(iii) concept of beam
balance
(c) Time
(i) unit of time
(ii) time-measuring
devices
(d) Fundamental
physical quantities
(e) Derived physical
quantities and their
units
(i) Combinations of
fundamental
quantities and
determination of their
units
(f) Dimensions
(i) definition of
dimensions
(ii) simple examples
(g) Limitations of
experimental
measurements
(i) accuracy of
measuring
instruments
(ii) simple estimation
of errors.
(iii) significant figures.
(iv) standard form.
(h) Measurement,
position, distance and
displacement
(i) concept of
displacement
(ii) distinction
between distance and
displacement
(iii) concept of
position and
coordinates
(iv) frame of reference
Candidates should be
able to:
i. identify the units of
length, area and
volume;
ii. use different
measuring
instruments;
iii. determine the
lengths, surface areas
and volume of regular
and irregular bodies;
iv. identify the unit of
mass;
v. use simple beam
balance, e.g Buchart's
balance and chemical
balance;
vi. identify the unit of
time;
vii. use different time-
measuring
devices;
viii. relate the
fundamental physical
quantities to their
units;
ix. deduce the units of
derived physical
quantities;
x. determine the
dimensions of
physical quantities;
xi. use the dimensions
to determine the units
of physical quantities;
xii. test the
homogeneity of an
equation;
xiii. determine the
accuracy of
measuring
instruments;
xiv. estimate simple
errors;
xv. express
measurements in
standard form.
Candidates should be
able to:
i. use strings, meter
ruler and engineering
calipers, vernier
calipers and
micrometer, screw
guage
ii. note the degree of
accuracy
iii. identify distance
travel in a specified
direction
iv. use compass and
protractor to locate
points/directions
v. use Cartesians
systems to locate
positions in x-y plane
vi. plot graph and
draw inference from
the graph.
2. Scalars and Vectors
(i) definition of scalar
and vector quantities
(ii) examples of scalar
and vector quantities
(iii) relative velocity
(iv) resolution of
vectors into two
perpendicular
directions including
graphical methods of
solution.
Candidates should be
able to:
i. distinguish between
scalar and vector
quantities;
ii. give examples of
scalar and vector
quantities;
iii. determine the
resultant of two or
more vectors;
iv. determine relative
velocity;
v. resolve vectors into
two perpendicular
components;
vi. use graphical
methods to solve
vector problems;
3. Motion
(a) Types of motion:
translational,
oscillatory, rotational,
spin and random
(b) Relative motion
(c) causes of motion
(d) Types of force
(i) contact
(ii) force field
(e) linear motion
(i) speed, velocity and
acceleration
(ii) equations of
uniformly accelerated
motion
(iii) motion under
gravity
(iv) distance-time
graph and velocity
time graph
(v) instantaneous
velocity and
acceleration.
(f) Projectiles:
(i) calculation of
range, maximum
height and time of
flight from the
ground and a height
(ii) applications of
projectile motion
(g) Newton's laws of
motion:
(i) inertia, mass and
force
(ii) relationship
between mass and
acceleration
(iii) impulse and
momentum
(iv) force - time graph
(v) conservation of
linear momentum
(Coefficient of
restitution not
necessary)
(h) Motion in a circle:
(i) angular velocity
and angular
acceleration
(ii) centripetal and
centrifugal forces.
(iii) applications
(i) Simple Harmonic
Motion (S.H.M):
(i) definition and
explanation of simple
harmonic motion
(ii) examples of
systems that execute
S.H.M
(iii) period, frequency
and amplitude of
S.H.M
(iv) velocity and
acceleration of S.H.M
(v) simple treatment
of energy change in
S.H.M
(vi) force vibration
and resonance
(simple treatment)
(iii) conservative and
non-conservative
fields
(iv) acceleration due
to gravity
(v) variation of g on
the earth's surface
(iv) distinction
between mass and
weight
(v) escape velocity
(vi) parking orbit and
weightlessness
Candidates should be
able to :
i. identify different
types of motion ;
ii. solve numerical
problem on collinear
motion;
iii. identify force as
cause of motion;
iv. identify push and
pull as form of force
v. identify electric and
magnetic attractions,
gravitational pull as
forms of field forces;
vi. differentiate
between speed,
velocity and
acceleration;
vii.deduce equations
of uniformly
accelerated motion;
viii. solve problems of
motion under gravity;
ix. interpret distance-
time graph and
velocity-time graph;
x. compute
instantaneous velocity
and acceleration
xi. establish
expressions for the
range, maximum
height and time of
flight of projectiles;
xii. solve problems
involving projectile
motion;
xiii. solve numerical
problems involving
impulse and
momentum;
xiv. interpretation of
area under force -
time graph
xv. interpret Newton's
laws of motion;
xvi. compare inertia,
mass and force;
xvii. deduce the
relationship between
mass and
acceleration;
xviii. interpret the law
of conservation of
linear momentum and
application
xix. establish
expression for
angular velocity,
angular acceleration
and centripetal force;
xx. solve numerical
problems involving
motion in a circle;
xxi. establish the
relationship between
period and frequency;
xxii. analyse the
energy changes
occurring during
S.H.M
xxiii. identify different
types of forced
vibration
xxiv. enumerate
applications of
resonance.
Candidates should be
able to:
i. identify the
expression for
gravitational force
between two bodies;
ii. apply Newton's law
of universal
gravitation;
iii. give examples of
conservative and non-
conservative fields;
iv. deduce the
expression for
gravitational field
potentials;
v. identify the causes
of variation of g on
the earth's surface;
vi. differentiate
between mass and
weight;
vii. determine escape
velocity
5. Equilibrium of
Forces
(a) equilibrium of
particles:
(i) equilibrium of
coplanar forces
(ii) triangles and
polygon of forces
(iii) Lami's theorem
(b) principles of
moments
(i) moment of a force
(ii) simple treatment
and moment of a
couple (torgue)
(iii) applications
(c) conditions for
equilibrium of rigid
bodies under the
action of parallel and
non-parallel forces
(i) resolution and
composition of forces
in two perpendicular
directions,
(ii) resultant and
equilibrant
(d) centre of gravity
and stability
(i) stable, unstable
and neutral equilibra
Candidates should be
able to:
i. apply the conditions
for the equilibrium of
coplanar forces to
solve problems;
ii. use triangle and
polygon laws of
forces to
solve equilibrium
problems;
iii. use Lami's theorem
to solve problems;
iv. analyse the
principle of moment
of a
force;
v. determine moment
of a force and couple;
vi. describe some
applications of
moment of a force
and couple;
vii. apply the
conditions for the
equilibrium
of rigid bodies to
solve problems;
viii. resolve forces into
two perpendicular
directions;
ix. determine the
resultant and
equilibrant
of forces;
x. differentiate
between stable,
unstablend neutral
equilibra.

View syllabus properly here


cc thankyoujesus
tobie
orezy5
others(i can't remember)

Geofavor:
View syllabus properly here


cc thankyoujesus
tobie
orezy5
others(i can't remember)

Presently, I am in church, I will try and do my best where possible and also, I will jump some topics with lot of diagrams because I am using a "small" phone. How are you fairing now?

thankyouJesus:
Presently, I am in church, I will try and do my best where possible and also, I will jump some topics with lot of diagrams because I am using a "small" phone. How are you fairing now?

alright. i'm better now, thanks.

Intoduction.
Good morning all, today will be our first class but before that, I need to point out some things;
1. Circumstances such as battery, megabytes, and other unforseen factors will greatly influence this class.
2. My strength is in computational physics (calculation) while + am above average in theoretical physics.
3. I will be resuming for my undergraduate studies at the University of Ibadan on February, my schedule thereon is what I can't guaranty.
4. I can't do this alone, pardon me to call on Prot0n, Mathefaro, Sexykaycee et al.
5. I may not move in line with JAMB brochure but, I will not go above, below, beyond (out is the right word) it.
6. Due to the fact I am using a local phone, I may/will jump some topics with lot of diagrams.
7. That is it for now, I will update later.
How to calculate in Physics.
1. You must be good with mathematics, if not, I will advice you equip yourself with a good textbooks or follow the mathematics JAMB thread.
2. Always writes out your parameters before calculating.
3. Don't waste time on questions you don't know. Make sure you pick an option.
4. Most physics formulae are interwoven, get the basic.
5. Understand the question before attempting.
6. Be familiar with your units.
7. Be open to more knowledge.
8. Above all, don't depend on this thread only, read, read, read and read.
9. Practise using past questions.
10. Physics is simple.

[b]I don't feel comfortable jumping into physics straigth away, allow me to start with science and other backgrounds.
Science.
Science is seen as a body of knowledge, proven fact and absolute truth which can be ascertain through specific proof/procedure embeded in the scientific method.
Physics.
Physics the most fundamental science is concerned with the basic principles of the universe. Physics enables us to answer questions about cause and effect relationship between physical events.
Physicist.
A physicist is a person who want to understand nature for the satisfaction of knowing. They are always developing theories to describe the physical world.
A physician is a medical/traditional practitioner.
Some areas of physics.
1. Mechanics; This is concerned with the effect of forces on material objects.
2. Thermodynamics/heat; Deals with heat, temperature and the behaviour of large number of particles.[/b]

[b]3. Light/optics; Deals with light, waves and wave optic.
4. Sound/acoustic; Deals with sound and sound waves.
5. Electromagnetic; combines electricity and magnetism and deals with charges, current and magnetic field.
6. Astronomy; Deals with far off physical bodies.
7. Waves and vibrations; Deals with oscillation and vibrations.
8. Nuclear Physics; Deals with nuclear particle, nuclear fusion etc.
9. Electronics; Deals with analogue and digital electronics.
10. Quantum Mechanics; Deals with behaviours of particles at a sub base microscopic level and macroeconomic level.
Career opportunities in physics.
1. Education (teacher, lecturer).
2. Communication/telecommunication (radio, radial, satellite, fibre optic).
3. Alternate energy (wind, solar, iso-thermal, geo-thermal).
4. Computing ( robotics, system design, micro processor control, computer aided design).
5. Engineering sector (electrical, mechanical aeronautical etc engineering).
6. Geo-physics ( oil prospecting, minerals, pathology, etymology).
7. Environmental science (pollution control, radiation protection, conservation).
8. Material science ( metallurgy, development of new materials).
9. Medical physics (health science instrumentation, radiaology)
10. Meterology (weather forecasting, oceanography, marine industry).
11. Industries (aerospace, chemical, petroleum, food etc).
12. Civil service/defense ( research, potency standardization).
Etc.
Notable physicist of old.
1. Sir Isaac Newton.
2. Nikola Tesla.
3. Marie Curie.
4. Tycho Brahe.
5. Galileo Galilei
6. Joahnes Keeper.
Etc[/b]

[b]Measurement and units.
Measurement play a vital role in Physics, but they can never be perfectly correct.
Measuring instruments.
Measuring instruments are tools used in getting exact measurement of objects.
Measurement of objects.
1. Mass;
a. Lever balance; This is used to measure mass directly in kilogram(Kg).
b. Chemical/beam balance; This is mostly used in measuring unknown mass.
2. Weight;
a. Spring balance; This is used to measure the weight of an object. Weight is measured in Newton(N).
3. Time;
a. Ticker tape timer; This is used to measure short intervals of time accurately.
b. Stop watch/clock; This is an instrument which is sued to determine the time used either in the laboratory or on the field during sporting activities.
c. Sand clock / hour glass; This is an instrument which is used to measure time per hour.
d. Simple pendulum; Mostly used in the laboratory to measure time.
e. Heart beat; Heart beat is a natural way of counting. It is mostly used in medical line. The heart beat gives the pressure and the rate of pumping of blood in the body. An increase in heart beat is an increase in blood pressure and vice versa.
4. Distance;
a. Metre rule; The metre rule is graduated in cm and mm.
Long distances such as the length or width of a large farm area or football field can be measure with steel tapes graduated in metres.
b. Micro metre screw gauge; This instrument is used to measure accurate diameter of objects.
c. Vernier callipers; Is used to measure in cm and mm.
Summary.
1. Mass- chemical or beam balance, level balance, electronic mass meter, triple beam balance.
2. Time- pendulum clock, water clock, hour glass, electric clock.
3. Power- wattmeter.
4. Speed- speedometer.
5. Velocity- velometer.
6. Depth- Sacchi disc.
7. Volume- beaker, conical flask, round bottom flask, burette, pipette.
8. Relative humidity- hygrometer.
9. Relative density- hydrometer.
10. Temperature- thermometer.
11. Height/altitude- metre rule, aneroid barometer (altimeters).
12. Solar rays (heat)- actinometer.
13. Magnetic declination- declinometer.
14. Darkness (degree)- densitometer.
15. Hardness- durometer.
16. Strength of magnetic field- magnetometer.
17. Illuminate or irradiance- photometer.
18. Solar radiation- pyranometer.
19. Location on Earth's surface- sextant.
20. Properties of light- spectrometer.
21. Response to applied forces- rheometer.
22. Current- ammemeter.
23. Voltage- voltmeter.[/b]

Finally, the thread has been created i'm pitching my tent right here.

DebbyChris:
Finally, the thread has been created i'm pitching my tent right here.

welcome . pls tag the others (some people told me to tag them when this thread is created, but now i can't remember their nicks)


btw,

let me join the group

Good morning all, how was the night? I was pondering on how best to point out salient points in write up, so I decided to always give it a background colour. Watch out for coloured words based on my experience in JAMB and which will also be a guide to this class.

[b]Mass and Weight.
Mass is defined as the quantity of matter in a body. It is measured in Kilogram (kg), e.g. The mass of a body such as bag, book etc.
The weight of an object is defined as the earth pull of the body, i.e. Force acting on an object due to gravitational pull of the Earth. It is measured in Newton(N). It is a vector quantity which varies from place to place on the Earth's surface because of the;
1. Distance of object to the centre of the Earth.
2. Shape of the Earth.
3. Force of attraction of the body to the centre of the Earth.
The relationship between the mass and weight is given by;
w=mg
where w is weight (N)
m is mass (kg)
g is acceleration due to gravity (m/s²).

---

Example; Calculate the weight of an object whose mass is 12kg. [g=10m/s².
Solution;
1. Write out the parameters given.
M=12kg
g=10m/s²
w=?
2. What is/are the relationship between the parameters?..............................very good.
W=mg.
3. Calculation
w= 12 X 10
w= 120
w= 120N (unit is very very very very important in physics).

---

Example; Calculate the weight of an object whose mass is 5000g. (g=10m/s²).
Solution; 1. Write out the parameters........very good but, the standard unit of mass is Kg not g.
2. Convert all unit(s) into standard unit in physics. Your knowledge in mathematics is needed here, if
1000g=1kg
5000g=?..........
Very good, 5kg.
3. The relationship is? Very good...............
W=mg
w= 5 X 10
W= 50N.

---

Example; Calculate the mass of an object whose weight is 45N. (g=10m/s²). Leave your answer in gram.
a. 4.5kg b. 4500g.
Solution; 1. Write out your parameters.
2. Relationship, w=mg.
3. calculation;
w=mg
45 = m X 10.
Mathematics again, this is change of subject.
Divide both sides by 10.
M = 4.5
the unit of m above is?..............very good kg.
M = 4.5kg. Option a is very very very correct but the conditional statement ruled it out.
4. Watch out for conditional statement, mathematics again, if
1kg=1000g. Then,
4.5kg=?...........very good, 4500g which is option b.

---

Note;
1. Acceleration due to gravity is more at the poles and less at the equator (this is due to reasons 1 and 2 above but 1 leads the way).
2. g_Earth=6g_moon (i.e. g on Moon is 6times g on Earth). Explanation; if two objects are dropped from equal height in Earth and Moon, the object on the Moon will get to the surface before the object on Earth.

---

Mass;
1. Mass is constant.
2. Mass is a scaler quantity.
3. Mass is the quantity of matter present in a body.
4. Unit is kg or g.
5. Mass is measured btw chemical/beam balance based on principle of moment.
Weight;
1. Weight varies.
2. Unit is Newton(N).
3. Weight is a vector quantity.
4. Weight is Earth's pull of the body.
5. Weight is measured by spring balance based on Hooke's law.[/b]

[b]Fundamental and Derived Units.
Fundamental units are the accepted standard units or measures in which measurement is made.
They are;
1. Metre as the unit of length.
2. Kilogram as the unit of mass.
3. Second as the unit of time.
4. Ampere as the unit of current.
5. Kelvin as unit of temperature.
6. Weber as unit of magnetic flux.
7. Candela as unit of luminous intensity.
Derived units are new units derived from fundamental units. They are derived from combinations of fundamental units.

---

Let us derive the unit of the following physical quantities together.
1. Area = length X breadth.
Length is measured in metre so also is breadth.
Area = m X m = m².
2. Volume = length X breadth X height.
Volume = m X m X m = m³.
3. Speed = distance/time.
Distance is measured in metre while time is in second.
Speed = metre/second = m/s.
4. Velocity = displacement/time.
Displacement is measured in metre.
Velocity = metre/time = m/s.
5. Density = mass/volume.
Mass is measured in kilogram.
Density = kilogram/metre³.
Density = kg/m³.

---

Fundamental and Derived Quantities.
Fundamental quantities are the basic quantities that provide the standard units of measurement. They are;
1. Length.
2. Mass.
3. Time.
4. Temperature.
5. Current.
6. Magnetic flux.
7. Luminous intensity.
Derived quantities are obtained from fundamental quantities. Examples include;
1. Charge = current X time.
2. Speed = distance/time.
Dimension of physical quantity.
Dimension of physical quantity simply means the way it is related, connected or associated to fundamental quantities.
The dimensions are;
1. M - mass.
2. L - length.
3. T - time.
4. K - temperature.
5. A - current.
6. II - luminous intensity.

---

Lets consider the dimension of some physical quantities together.
1. Speed = distance/time.
The dimension of distance is m,...................opps, you are wrong, that's the unit, the dimension is L while the dimension of time is?..............................very good, T.
Speed = L/T.
2. Velocity = displacement/time.
The dimension of displacement is?...........................L, very good.
Velocity = L/T.
3. Momentum = mass X velocity.
The dimension of mass is? Very good, M.
Momentum = ML/T.
End of discussion for this topic, any question?[/b]
Don't confuse unit with dimension, I do make the mistake. Get your game right.
This is just the beginning of physics, the ride will be long and bumpy, before that, any question, suggestion, query, opinion, interjection?

Following

thankyouJesus:
Intoduction.
Good morning all, today will be our first class but before that, I need to point out some things;
1. Circumstances such as battery, megabytes, and other unforseen factors will greatly influence this class.
2. My strength is in computational physics (calculation) while + am above average in theoretical physics.
3. I will be resuming for my undergraduate studies at the University of Ibadan on February, my schedule thereon is what I can't guaranty.
4. I can't do this alone, pardon me to call on Prot0n, Mathefaro, Sexykaycee et al.
5. I may not move in line with JAMB brochure but, I will not go above, below, beyond (out is the right word) it.
6. Due to the fact I am using a local phone, I may/will jump some topics with lot of diagrams.
7. That is it for now, I will update later.
How to calculate in Physics.
1. You must be good with mathematics, if not, I will advice you equip yourself with a good textbooks or follow the mathematics JAMB thread.
2. Always writes out your parameters before calculating.
3. Don't waste time on questions you don't know. Make sure you pick an option.
4. Most physics formulae are interwoven, get the basic.
5. Understand the question before attempting.
6. Be familiar with your units.
7. Be open to more knowledge.
8. Above all, don't depend on this thread only, read, read, read and read.
9. Practise using past questions.
10. Physics is simple.

we dey your back bro

SexyKaycee:


we dey your back bro

Ope o, to type no be for here o, na job typist dey do o.

Busy schedule, we will continue tomorrow.

[b]Good morning all, how are you finding the class? Lovely, I know. Lets continue with the discussion.
Motion.
Many scientists have studied motion and its properties because of its importance to life. The Italian, Galileo Galilei did the first systematic study of motion. Also, Sir Isaac Newton did more detailed work on the study of motion.
Motion involves a change of position of a body with time. It also involves how things move and what makes them to move. It exists in different forms and occurs in solids, liquids, and gases.
Motion is defined as the change of position of a body with time.
Types of Motion.
There are five types of motion, which are; translational rectilinear motion, random motion, oscillatory motion, rotational motion and relative motion.
1. Translational rectilinear motion; This type of motion occurs when an object moves in a fixed direction. When a body moves in a fixed direction, the body is said to be translated. Examples are; movement of a car from a point to another, human movement from a point to another:
2. Random motion; This sis a type of motion in which a body moves in a non-linear manner and changes direction continuously. Examples are; molecular movement in gases, dashing of objects in air eg feather thrown into air.
3. Oscillatory motion; This is a to and fro movement about a fixed point. It arises due to a slight displacement of an object from the initial position to a new position and back to the initial position. Examples are; simple pendulum, vibration of plucked guitar strings.
4. Rotational motion; This is the movement of a body in a rotational manner about its axis. Examples are; rotation of electric fan blades, movement of car wheels.
5. Relative motion; Is the movement of object in relation to another body. A car travelling on a road side is said to be in motion with respect to the poles and the trees on the road side. Examples are; pulling on a spinal spring, bending a ruler on a beam.[/b]

[b]Causes of Motion.
Force causes motion. When force is applied on any object, it causes change. Force is a vector quantity denoted by F and measured in Newton(N).
Types of Force.
There are two types of force, which are the contact force and force field.
1. Contact force; This exists when there is a touch, hold or a contact with the object in question. It is further divided into like force or push, unlike force or pull and fictional force or viscous.
2. Force field; This exists in or is confined/restricted to a given region or space, i.e., a region in space where a body experiences the effect of a force which occurs as a result of the influence of some physical agencies. It is further divide into; magnetic force, gravitational force and electric force.
a. Magnetic force; This is a force that attracts magnetic substance eg nails.
b. Gravitational force; This is a force that attracts or pulls objects irrespective of their masses towards the centre of the Earth's surface.
c. Electric force; This is a force that keeps current through a conductor of electricity.[/b]

[b]Circular Motion.
Circular motion is a motion in a circular path in which the speed of the body remains constant while its direction continuously changes eg the Earth moving round the sun, a racing car moving round a circular track.
The velocity of a body undergoing circular motion is given by;
v = wr
where v is linear velocity (m/s)
w is angular velocity (rad/sec)
r is radius (m).
The acceleration is given by;
a = vw, or
a = (wr)w = w²r, or
a = v(v/r) = v²/r.
Centripetal force.
This is the force required to keep object moving in a circular path.
Mathematically;
f = ma
f = mvw, or
f = mv²/r, or
f = mw²r.
Where f is force (N)
m is mass (kg)
a is acceleration (m/s²).

---

Example; An object of mass 4kg moves in a circle at radius 8m at unformed speed of 32m/s. Calculate; (a) the angular velocity (b) the centripetal force.
Solution;
m = 4kg
r = 8m
v = 32m/s.
(a) v =wr
w = v/r
w = 32/8
w = 4rad/sec.
(b) f = mw²r.
F = 4 X 4 X 4 X 8
f = 512N.
Any question?[/b].

For me, no question. ... I am feeling you die. Ride on! Cc thankyoujesus

Geofavor:
For me, no question. ... I am feeling you die. Ride on! Cc thankyoujesus

My boss, na your face I dey look o.

thankyouJesus:
My boss, na your face I dey look o.

i really appreciate your effort, sir. You're doing great, both here and in the maths thread. I just hope you'll keep this up and not stop abruptly. More power to your elbow

Geofavor:

i really appreciate your effort, sir. You're doing great, both here and in the maths thread. I just hope you'll keep this up and not stop abruptly. More power to your elbow

okay sir

[b]Good morning all.
Elasticity.
Elasticity is the ability of a material to regain its original shape or size after deformation. Deformation is elastic if the wire returns to its original position, while it is plastic if it does not return to its original position.
Terms used in elasticity.
1. Elastic limit; Elastic limit is the maximum load (force) which a body can experience and still retain its original size/shape. It can also be defined as the point which Hooke's law is no longer obeyed.
2. Yield point; Yield point is reached when a stretched wire does not return to its original position.
3. Maximum load; When a load is added to a wire that it cannot stand any further increase, it is called maximum load.
4. Breaking point; Breaking point is the point at which the wire breaks away from the original.
Hooke's law.
It states that the force applied to a spring is directly proportional to the extension produced, provided the proportionality limit is not exceeded.
Mathematically;
F ~ E
F = KE
where K is constant (N/m).

---

Example; The extension on a spring when 5g was hung from it was 0.56cm. If Hooke's law is obeyed, what is the extension caused by a load of 20g.
Solution;
F₁=5g
E₁=0.56cm
F₂=20g
E₂=x
F₁/E₁=F₂/E₂.
5/0.56 = 20/x
5x = 0.56 X 20
x = 2.24cm[/b]

[b]Strength of Material.
1. Tensile/Compressive stress; This is the ratio of load/force to its area. It is measured in N/m².
Mathematically;
Stress = force/area.
2. Tensile/Compressive strain; Is the ratio of extension to original length. It has no unit.
Mathematically;
Strain = extension/length.
3. Young modules; This is the ratio of stress to strain. It is denoted by E and measured in N/m².
Mathematically;
E = stress/strain = (F/A) / (E/L)
E = (F/A) X (L/E) = FL/AE.
4. Force/elastic constant or stiffness; This is the amount of force that causes a unit extension of an elastic material or the ratio of force to extension of an elastic. It is denoted by K, measured in N/m.
Mathematically;
K = F/e.

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Example; A load of 20N on a wire of cross sectional area 8X10^-7m² produces an extension of 10^-4m. Calculate young modulus for the material of the wire if its length is 3m.
Solution;
F = 20N
A = 8X10^-7m²
e = 10^-4m
L = 3m
stress = F/A = (20)/(8X10^-7
stress = 2.5X10⁷N/m².
Strain = E/L = 10^-4/3
strain = 3.33X10^-5.
Young modulus = stress/strain.
E = 7.5X10¹¹N/m².[/b]

DebbyChris:
Finally, the thread has been created i'm pitching my tent right here.

thankyouJesus:
Classwork.
1. A wire of length 5m and diameter 2mm extends by 0.25mm when a force of 50N was used to stretch it from its end. Calculate (a) strain (b) stress in the wire. (Hint; unit and area of circle).
2. A spiral spring of a spring balance is 25cm long when it is 10N. What is the length of the spring in 0.5kg, assuming Hooke's law is obeyed?(g=10m/s²)(Hint; F=w=mg).
3. A spring of force constant 1500N/m is acted upon by a constant force of 45N. Calculate the potential energy stored in the spring. (Hint; h=e, f=mg).

Slimbeth:
let me join the group

thankyouJesus:
Classwork.
1. A wire of length 5m and diameter 2mm extends by 0.25mm when a force of 50N was used to stretch it from its end. Calculate (a) strain (b) stress in the wire. (Hint; unit and area of circle).
2. A spiral spring of a spring balance is 25cm long when it is 10N. What is the length of the spring in 0.5kg, assuming Hooke's law is obeyed?(g=10m/s²)(Hint; F=w=mg).
3. A spring of force constant 1500N/m is acted upon by a constant force of 45N. Calculate the potential energy stored in the spring. (Hint; h=e, f=mg).

There is no crime in trying, we are all here to learn.

Strain 5*10~-5 stress 15.9*10~6

2. 1.25m 3. 1498.5J am not sure of no.3 cc.thankyoujesus