This document summarizes key concepts in physics including: 1. It defines physics as the branch of science that studies natural phenomena and defines physical quantities that can be measured like length, mass, and time. 2. It discusses scalar and vector quantities, units of measurement, accuracy and precision of instruments, and types of errors that can occur when measuring physical quantities. 3. It also covers concepts in mechanics like displacement, velocity, acceleration, forces, momentum, energy, work, power, and laws of motion. 4. Additional topics covered include properties of matter, fluids, heat, light, and optics principles like reflection, refraction, and lenses.

1. - Is a branch of sciences
which studies physical and
natural phenomenon
-physical quantity that can
be measured
-is a physical quantity produced
from the combination of base
quantities through
multiplication, division or both
-physical quantity which
can not be defined in
terms of other physical
quantity
Length,l Meter,m
Mass,m Kilogram,kg
Time,t Second,s
Temperature,T Kelvin,K
Current,I Ampere,A
-physical quantity that
has magnitude only
-eg: distance, length,
mass, volume, speed
-physical quantity that
have both magnitude
and direction
-eg: velocity, force,
weight, displacement

2. -the ability of the
instrument to give
consistent readings when
the same physical quantity
is measure more than once
-the ability of the
instrument to give
measurements of physical
quantity which are close to
the actual value
-the ability of the instrument
to detect small changes in a
quantity measured
-an error in reading scale
when a physical quantity is
being measured
-occur when the
reading show on the
instrument is not zero
-occurs when the observer is
reading the scale on the
measuring instrument
-occur when a reading is
taken from an unsuitable
position relative to the
scale
-adjust the pointer of the scale
intrument to zero before use it
-make sure the eye is perpendicular
to the scale of the instrument

3. -total route taken by a motion
-scalar quantity
-distance taken consideration of
direction
-vector quantity
-rate of change of distance
-scalar quantity
-rate of change of displacement
-vector quantity
Unit-ms-1
-the rate of change of velocity
-vector quantity
-object move slower and slower
-negative acceleration
Unit-ms-2
1.
2. v=u+at
3. s=ut+1/2at2
4. v2=u2+2as
Graph of motion
1. displacement-time
2. Velocity-time

4. -state that :
(a) An object which is at rest
will remain stationary
(b) An object is moving with
constant velocity will
continue moving unless
there are external force
acting on it
(c) An object will maintain its
state of rest or of uniform
motion provided there are
no external forces acting on
it.
State that;
- The rate of change of
momentum of a object is
proportional to the force
applied and takes place
in the direction in which
the force acts.
State that;
-to every action there is
an equal and opposite
reaction

5. State that; Apply in
-the extension of a spring
is proportional to the
applied force, provided
the elastic limit is not
exceeded
l  F
Elasticity

6. -define as the property of matter to
resist any change in its motion
Newton’s 1st law
-relate to
mass of the
object
-bigger mass bigger
inertia
-smaller mass
smaller inertia
Eg;
1. pushing a
big rock
2. Kicking a ball
Eg;
1. Elephant
chasing a chile
2. To pour out of
chili sauce
3. To tighten the
head of a
hammer
Eg;
1. Passenger in the bus will throw to the front
when the driver stop the bus suddenly
2. Container ship need over an hour to accelerate
to its full speed or slow down to stop

7. -define as a product
of mass and
velocity
P = mass x velocity
-vector quantity
Unit; kgms-1
Increases when
1. Mass increases
2. Velocity
increases
3. Both mass and
velocity
increases
apply
State that;
-the total linear momentum
of a closed system of bodies
is constant(total momentum
before collision is equal to the
total momentum after
collision
elastic inelastic explosion
-both object separate
after collision
-both object will move
together after collision
-two or more objects in
contact will be separated
after collision
m1u1+m2u2=m1v1+m2v2 m1u1+m2u2=(m1+m2)v (m1+m2)u=m1v1+m2v2
Total momentum and
total energy are
conserved
Total momentum and
total energy are
conserved
Total momentum and
total energy are
conserved
Total kinetic energy
conserved
Total kinetic energy is not
conserved
Total kinetic energy is
not conserved
applications
1. Rocket
2. The water hose
3. Billiards and
bowling games

8. -an action which will alter the
state of motion of a
body/object in a straight line
define as
-vector quantity
-unit; Newton (N)
Alter body /object
size, shape, state of motion, direction
of motion and speed
types -in a condition
body/object does
not change the state
of rest or motion.
-eg; stationary car
an aeroplane flying
at constant velocity
-when the force acting on the
object/body
-unbalanced forced=net
force/resultant force
10 N3 N
Unbalanced force= 10 – 3 N
= 7 N
F=ma
-define as the change
of momentum
-Ft=mv-mu (kgms-1
or Ns)
-rate of change of momentum
-impulsive force=impulse/time
-unit; kgms-2 or N
applied in car safety feature design
Force in equilibrium,
net force is zero

9. -gravitational force acting per
unit mass on an object in the
field, (g=10 m/s2)
-define as the force of gravity
acting on object
-vector quantity
-influence by the acceleration
due to gravity, g
W=mg
-any object which fall only
under the influence of the
force of attraction due to
gravity and without any
influence of other force
Object fall with the same acceleration due to gravity,
g=10 m/s2
-is not influenced by the mass of an
object
-influenced by the other force which
is air resistance
- When two object are
released at the same height
simultaneously, they will
reach to the bottom at the
same time
VACUUM- A SPACE WITH NO AIR

10. -Define as;the product of
the force and the
displacement of an object
in the direction of the
force
Work done= F x s
need energy
- define as the potential or the
ability to do work
- Energy caused by
an object due to
its position or rate
Depend on;
1. Mass
2. Height
3. Gravitational
field
Potential energy=Work done=mgh
- define as the energy caused
by an object due to its motion
Kinetic energy=work done=
1/2 mv2
PRINCIPLE OF CONSERVATION
OF ENERGY
State that;
Energy can not be
destroyed or created but
it can change from one
form to another
-define as; the rate at which work
is done or the rate of change of
energy. (unit; watt,W)
Depend on time taken and work done

11. -spring is stretch and compressed
HOOKE’S LAW APPLY
-state that;
The extension of a
spring is proportional
to the force applied to
it, provided the elastic
limit is not exceeded
equation
k - spring constant
k=gradient of graph F-x
1. Length of spring(longer spring,
bigger extension)
2. Diameter of the coil of spring
(bigger diameter, bigger
extension)
3. Type of material (more flexible,
more extension) eg; copper
more flexible than steel.
4. Cross sectional area of wire
which form the spring ( thinner
wire, more extension)
5. Arrangement of the springs
(spring arranged in series will
give a greater extension)
Work done by a
spring;
W=1/2 Fx=Ep

13. -Force per unit area
define as
Unit, Pascal(Pa)
P=hg
-P depends on;
1. Depth (depth, P )
2. Density (density , P)
3. Gravitational field strength
-properties;
1. Pressure act at all directions
2. Pressure at the same height
is equal
-caused by the collision of gas
molecules moving randomly in
the container
-measured by using manometer
and Bourdon Gauge
-caused by the weight of
air above us
-value of 1atm is 76 cm Hg
-Instrument use; aneroid
barometer and Fortin
Barometer.
moving liquid
-pressure applied to a fluid in
a closed vessel is transmitted
equally to every point in a
liquid
- eg; hydraulic system
state that;
When the speed of a
fluid increase, the
internal pressure in the
fluid decrease and vice
versa
-applications;
1. Bunsen burner
2. Aerofoil in aircraft
wing
3. Bug sprayer

14. Archimedes’
Principle
State that;
-when an object is wholly
or partially immersed in
a fluid, it experiences a
buoyant force equal to
the weight of water
displaced.
Upthrust = weight of the water displaced
Vg = mg
1.  object >  fluid
2. Weight of object>upthrust
3. V fluid displaced = V object
4. Upthrust=weight of the fluid displaced
1. Weight of object = upthrust
2. V fluid displaced ≠ V object
= V object immersed in fluid
1. Submarine
2. Hot air ballon
3. Hydrometer
4. Ship

16. HEAT
-measure the hotness of
the body
temperature
- Transfer energy from
a hot object to a cold
object until both reach
the same temperature
Thermal equilibrium
-two object in thermal contact
with same temp.(no heat transfer
between them)
-the amount of heat that
required to raise its
temperature of 1kg of the
substance by 1 C
-
(Jkg-1C-1)
-heat energy required to melt
1 kg of the substance at its
melting point without change
in temperature (solid to liquid)
-Q=ml
-is the heat energy required
to change 1 kg of the
substance from liquid to gas
at boiling point without
change of temperature
-Q=ml

17. -State that;
For a fixed mass of gas at constant
pressure , the volume of the gas is
directly proportional to its absolute
temperature(kelvin scale of
temperature)
-state that;
For a fixed mass of gas at constant
temperature, the volume of the
gas in inversely proportional to its
pressure
-state that;
Pressure of a fixed mass of gas at
constant volume is directly
proportional to its absolute
temperature
0 K = -273 C
Kinetic theory of gas;
gases has zero volume
and pressure
- TC=(T+273) K

18. LIGHT

19. Law of reflection
-state that;
(a) Angle of incidence=angle of reflection
(b) The incident ray, the reflected ray and the
normal at the point of incidence are in the
same plane
-image formed by plane mirror;
(a) Same size as the object
(b) As far behind the mirror as
the object is in front
(c) Virtual
(d) Upright
(e) Laterally inverted
-image formed by convex mirror ;
(a) Virtual
(b) Upright
(c) Smaller than object
-bending of light when it passes from
one medium to another(because of
the change of velocity of light and
density of medium)
-obeys;
1. Law of reflection
-the incident ray, refracted ray and
normal line lies on the same plane.
- the ratio of sin i to the sin r is
constant
2. Snell’s Law :
1. Light passes from a
less dense medium
to a denser
medium, ray
refracted toward
the normal
2. Light passes from a
denser medium to
less dense
medium, ray
refracted away
from normal

20. -Condition;
(a) The light ray must pass from a
denser medium to a less
dense medium
(b) The of incidence must be
greater than the critical angle
- Converging lens
- Diverging lens
Linear magnification,
f-focal length
u-object distance
V-image distance
Application; periscope
Applications;
-camera, spectacles,
magnifying glass,
microscope and other
optical instrument