Physics Equation List :Form 4

Introduction to Physics

Relative Deviation

Relative Deviation = Mean Deviation ×100% Mean Value

Prefixes Prefixes Tera Giga Mega Kilo deci centi milli micro nano pico Units for Area and Volume 1 m = 102 cm 1 m = 10 cm 2 4 2

Value 1 000 000 000 000 1 000 000 000 1 000 000 1 000 0.1 0.01 0.001 0.000 001 0.000 000 001 0.000 000 000 001

Standard form 1012 109 106 103 10-1 10-2 10-3 10-6 10-9 10-12

Symbol T G M k d c m μ n p

(100 cm) (10,000 cm ) (1,000,000 cm3)

2

1 cm

= 10-2 m

(

1 m) 100

1 m3 = 106 cm3

1 cm2 = 10-4 m2

(

1 m2 ) 10,000 1 m3 ) 1,000,000

1 cm3 = 10-6 m3

(

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Average Speed

Force and Motion

Average Speed = Total Distance Total Time

Velocity

v= s t

Acceleration

v = velocity s = displacement t = time

(ms-1) (m) (s)

a=

v−u t

a = acceleration v = final velocity u = initial velocity t =time for the velocity change

(ms-2) (ms-1) (ms-1) (s)

Equation of Linear Motion

Linear Motion

Motion with constant velocity

Motion with constant acceleration

Motion with changing acceleration

v=

s t

v = u + at 1 s = (u + v)t 2

Using Calculus (In Additional Mathematics Syllabus)

1 s = ut + at 2 2

v 2 = u 2 + 2as

u = initial velocity v = final velocity a = acceleration s = displacement t = time (ms-1) (ms-1) (ms-2) (m) (s)

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Ticker Tape

Finding Velocity:

velocity =

s number of ticks × 0.02s

1 tick = 0.02s

Finding Acceleration:

v−u a= t

a = acceleration v = final velocity u = initial velocity t = time for the velocity change (ms-2) (ms-1) (ms-1) (s)

Graph of Motion Gradient of a Graph The gradient 'm' of a line segment between two points and is defined as follows: Gradient, m = or m= Δy Δx Change in y coordinate, Δy Change in x coordinate, Δx

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Displacement-Time Graph Velocity-Time Graph

Gradient = Velocity (ms-1)

Gradient = Acceleration (ms-2) Area in between Displacement the graph and x-axis =

Momentum

p = m×v

p = momentum m = mass v = velocity

(kg ms-1) (kg) (ms-1)

Principle of Conservation of Momentum

m1u1 + m2u2 = m1v1 + m2 v2

m1 = mass of object 1 m2 = mass of object 2 u1 = initial velocity of object 1 u2 = initial velocity of object 2 v1 = final velocity of object 1 v2 = final velocity of object 2 Newton’s Law of Motion Newton’s First Law In the absence of external forces, an object at rest remains at rest and an object in motion continues in motion with a constant velocity (that is, with a constant speed in a straight line). (kg) (kg) (ms-1) (ms-1) (ms-1) (ms-1)

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Newton’s Second Law

mv − mu Fα t

The rate of change of momentum of a body is directly proportional to the resultant force acting on the body and is in the same direction. F = Net Force m = mass a = acceleration (N or kgms-2) (kg) (ms-2)

F = ma

Implication When there is resultant force acting on an object, the object will accelerate (moving faster, moving slower or change direction). Newton’s Third Law Newton's third law of motion states that for every force, there is a reaction force with the same magnitude but in the opposite direction. Impulse

Impulse = Ft

F = force t = time m = mass v = final velocity u = initial velocity

(N) (s) (kg) (ms-1) (ms-1)

Impulse = mv − mu

Impulsive Force

F=

mv − mu t

F = Force t = time m = mass v = final velocity u = initial velocity

(N or kgms-2) (s) (kg) (ms-1) (ms-1)

Gravitational Field Strength

F g= m

Weight

g = gravitational field strength F = gravitational force m = mass

(N kg-1) (N or kgms-2) (kg)

W = mg

W = Weight (N or kgms-2) m = mass (kg) g = gravitational field strength/gravitational acceleration

(ms-2)...