As fast as you can!

....describes the movement of the object.

Velocity-is an objects speed in a stated direction. This is called the vector quantity. The direction of velocity is indicated by a - or + sign. If a car was travelling +40mph and another is travelling -40mph they are simply traveling in oppisite directions.

Displacement is used to describe the distance covered in a certain direction. It is another vector quanity.

The accelertaion of an object is the rate at which its velocit changes. It is a measure of how quickly an object is speeding up or how slowly an object is slowing down.It is measure in m/s(2)

The slope of a velocity time graph represents the acceleration of an object- (the steeper the gradient the greater the acceleration). The area underneath the line represents the total distance travelled.

Forces- are pushes or pulls. eg friction, weight and air resistance. Forces may be different sizes and act in different directions. It is measured in NEWTONS (N)

Stationary objects- have equal forces acting upon them

Action force- When object A pushes of pulls object B

Reaction force-When object B pushes or pulls object A

Resultant force- is the balance of forces acting upon something.

Accelerating- When the driving force is greater that the resistive force.

Braking-When the resistive force is greater than the driving force

Moving at a constant speed-When the driving an resitive force are equal

If an unbalanced force acts on an object then the acceleration of the object will depend on...

• the size of the unbalanced force-the bigger the force, the greater the acceleration
• the mass of the object-the bigger the mass, the smaller the acceleration.

the constant velocity reached by a falling body (gravitational force is equal to the frictional forces acting upon it).

Falling objects experience two forces...

• the downward force of weight which always stays the same 
• the upward force of resistance or drag

Stopping Distances-

depend on the thinking distance and the braking distance.

Factors affecting stopping distances..

The speed of the vehicle

The mass of tehe vehicle

The conditions of the vehicle and road

The drivers reaction time

Momentum- is the measure of the state of movement of an object. It is dependant on two things;

The mass of the object

The Velocity of the object

cars have a lot of safety features to try and minimise injury and reduce the number of deaths;

• crumple zones- absorb momentum
• power assisted steering and anti-lock brake systmes- help the driver control direction
• cushioing during impact
• seatbelts which lock when the car brakes

imposed risk - eg coal mining, operating machinery

voluntary- smoking, rock climbing

Displacement- a disnce covered in a certain direction

Magnitude- a measure of size

Vector- a quanity that has both size and direction