SPM Revision Notes

PHYSICS: Topics 1 to 5

Mechanics, Heat and Light

Units

Base Quantity

SI Unit

Symbol

Mass, m

kilogram

Kg

Length, l

meter

m

Time, t

second

s

Temperature, T

kelvin

K

Current, I

ampere

A

Prefix

Value

Symbol

Example

giga

× 109

G

gigawat

Symbol for

example

GW

mega

× 106

M

megawat

MW

kilo

× 103

k

kilometer

km

deci

× 10-1

d

decimeter

dm

cent

× 10-2

c

centmeter

cm

milli

× 10-3

m

millimeter

mm

micro

× 10-6

μ

micrometer

μm

Scalar and Vector Quanttes

• Scalar quanttes are physical quanttes with only

magnitude.

• Vector quanttes are physical quanttes having both

magnitude and directon.

Scalar Quantities

Vector Quantities

Distance

Displacement

Speed

Velocity

Mass

Weight

Energy

Momentum

Temperature

Pressure

Time

Acceleraton

Power

Force

Density

Impulse

Force and Moton

change of distance

speed

time taken

total distance travelled

average speed

total time taken

change in velocity v u

acceleration, a

time taken

t

Equatons of Linear Moton with Uniform

Acceleraton

u v

s

t

2

v u at

1 2

s ut at

2

v 2 u 2 2as

s : displacement

u : initial velocity v : final velocity

t : time taken

a : acceleration

Newton’s Laws

• 1st Law of moton: (Law of inerta)

– Every object will contnue in its state of moton with uniform

velocity or at rest unless it is acted upon by an external force.

• 2nd Law of moton:

– If an external resultant force acts on the object, it will produce

a change in moton (called acceleraton) which is proportonal

to the force and inversely proportonal to the mass of the

object, ie. F = ma

• 3rd Law of moton:

– For every acton (force), there is an equal and opposite

reacton (force).

Momentum

• Momentum is the product of mass and

velocity, p =...