Physics AS Mechanics Unit 2

Set of revision cards containing definitions and equations included in specification.


Force x perpendicular distance

1 of 29

A Vector is...

...A physical quantity with both magnitude and direction

2 of 29

A Scalar is...

...A physical quantity with magnitude only

3 of 29


Change in distance / Change in time

4 of 29


Change in velocity / Change in time

5 of 29

Equations of Motion

v = u + at

2s = (u+v) x t

v^2 = u^2 + 2as

s = ut + 0.5 x a x t^2

6 of 29


Mass x Acceleration

7 of 29

Work Done (Energy Transferred)

Force x distance moved

8 of 29

Kinetic Energy

0.5 x m x v^2

9 of 29

Gravitational Potential Energy (GPE)

m x g x (change in h)

10 of 29

Elastic Potential Energy

0.5 x k x e^2

11 of 29

Work done to overcome friction

mgh - 0.5 x m x v^2

12 of 29


The rate of transfer of energy

Measured in Watts. 

13 of 29

Equations of Power

Energy transferred / time

Work done / time

Force x Velocity 

14 of 29

The efficiency of a machine..

useful energy transferred by the machine / total energy supplied into the machine

15 of 29

Principle of Conservation of Energy

Energy cannot be destroyed or created, it can only be turned into different forms.

16 of 29

Joules (J)

Energy is measured in Joules.

One Joule is defined as the energy required to move an object of weight 1N through a distance of 1m. 

17 of 29

Watt (W)

Power is measured in Watts.

One Watt is defined as a rate of transfer of energy equal to 1 Joule per second. 

18 of 29

Components of Force

Horizontal = F cos theta

Vertical = F sin theta 

19 of 29

The Principle of Moments

Sum of Clockwise moments = Sum of Anti-clockwise moments

20 of 29

Distance travelled

Speed x time

21 of 29

Distance travelled

Area under the line of a speed-time graph

22 of 29

Projectile Motion

Horizontal component = initial speed x time

Vertical Component = 0.5 x gravity x time^2 

23 of 29

Newton's Laws

First Law

Objects either stay at rest or remain in uniform motion in the same direction unless acted on by an external force

Second Law 

Force = mass x acceleration

Third Law (Law of Inertia)

Weight = mass x gravity 

24 of 29

Thinking Distance

The distance travelled in the time it takes the driver to react to the hazard.

Speed x reaction time 

25 of 29

Braking Distance

The distance it takes for the car to stop completely once the driver has reacted.

v^2 / 2a 

26 of 29

Stopping Distance

Thinking distance + Braking Distance

27 of 29

What factors might affect stopping distance?

  • Greasy/icy road
  • Medication/Drugs
  • Alcohol
  • Road conditions
  • Weather
  • Tyre conditions 
28 of 29

What safety features does a car have, and what do

  • Vehicle Bumpers
  • Airbags
  • Collapsible Steering Wheel
  • Crumple zones
  • Seat Belts

They all increase impact time, which reduces impact force, which lessens the force of the crash on the driver.

29 of 29


No comments have yet been made

Similar Physics resources:

See all Physics resources »See all Forces resources »