Forces

Multi-choice test

Revision Q/A

interpret distance-time graphs.  

 state and be able to use the equation  speed (m/s) = distance (m) / time (s)

 plot and

 calculate  graph.

 plot and interpret speed-time graphs.

 calculate

 describe how braking distance is affected by the road surface, the mass and speed of the vehicle.    

 describe factors that affect the thinking distance.

 recall that stopping distance is the sum of the thinking distance and the braking distance.    

 use the equation energy transferred = force x distance = 1/2 mv²  to discuss stopping distances.

 recall that velocity describes the speed and direction of a moving object.

 calculate 

 state and be able to use the equation acceleration = change in velocity time taken  acceleration (m/s squared) = v (m/s) / t (s)

 calculate

 describe the relative sizes of the horizontal forces on an object moving in a straight line when it is accelerating, decelerating and moving at constant speed. . 

 state and be able use to the equation   F (Newtons) = m (kg) x a (m/s squared)

 apply this relationship to the action of seat-belts and crumple zones.

 describe forces acting between objects.

 recognise that when object A pulls or pushes object B then object B pulls or pushes object A with an equal-sized force in the opposite direction.

Forces on falling objects

 describe the effects of the Earth's pull and resistive forces due to motion in a fluid.

 state and be able use the equation weight = mass × gravitational field strength.  weight (Newtons) = mass (kg) x g (approx  N/kg)

 explain how the size of the resistive force depends on the speed of the object.

 describe how the forces acting on an object falling at terminal velocity are balanced.