is a non–contact force that attracts objects with mass towards each other

is a force of a fluid on an object moving through it, in the opposite direction to the object’s motion

is the overall effect of the forces acting on an object

is the velocity of an object falling through a fluid, when there is zero resultant force

Terminal velocity

Physics

Newton’s Third Law (with free body diagrams in 2D)

Resultant forces and their effects

Forces in two dimensions

Moments, levers and gears

Balancing

Force, mass and acceleration (a = (v – u)/t)

Newton's Second Law (including inertia)

Stopping (and estimating stopping distances)

Conservation of momentum

Changing momentum

Stopping safely

In the Gravity in space unit, they will build on this knowledge to learn about centripetal forces, orbital motion, stellar evolution, red shift and the big bang.

In the Energy of moving objects unit, pupils learnt how to calculate the amount of energy of objects have because they are moving, stretched or in a gravitational field; and to calculate energy transfers using knowledge of energy conservation and dissipation.

This unit explores forces, interactions, and Newton’s laws, including motion, rotation, and momentum. It covers reaction times, stopping distances, and deceleration dangers. Emphasis is on force diagrams, calculations, experiments, and evaluating methods for accuracy and safety.

Forces make things change

Physical activity and equipment requiring safe use

non–contact force that attracts objects with mass towards each other

the force of a fluid acting on an object moving through it

the overall effect of the forces acting on an object

the velocity of a falling object when there is no resultant force

Match the following key terms about terminal velocity to the correct description.

the object will continue to accelerate as there is only one force acting on it

the drag force increases as the speed of the falling object increases

the weight of the object increases as the speed of the object increases

at terminal velocity, the drag force is equal to the weight of the object

at terminal velocity, the drag force is greater than the weight of the object

Which of the following statements about an object falling through the atmosphere are correct?

Object A: gravitational force = 40 N, drag force = 20 N

Object B: gravitational force = 200 N, drag force = 400 N

Object C: gravitational force =  200 N, drag force = 200 N

Object D: gravitational force = 200 N, drag force = 190 N

Object E: gravitational force = 0.4 N, drag force = 0.4 N

Five objects, A, B, C, D and E, are falling towards Earth. There are two forces acting on each object, the values of which are listed below.
Which of the objects are at terminal velocity?

acceleration is zero: object has reached terminal velocity

A velocity–time graph for a falling object is shown. Match the labelled points to the correct descriptions.

A stone of mass 0.5 kg is falling in water. Its weight is 5.0 N and a drag force of 4.5 N is acting.
Calculate the acceleration of the stone.
You do not need to give the unit.

the drag force on the balls will be equal at their terminal velocities

the drag force increases with the speed of the falling objects

terminal velocity is reached when the drag force equals the weight

the weight of the balls changes as they fall

the heavy ball has a larger drag when it is at the same speed as the light ball

Two balls, with the same diameter but different weights, are dropped from a height. 
Which two statements explain why the heavier ball reaches a higher terminal velocity then the lighter ball?

Which of the following forces acts on all objects near Earth surface?

An aeroplane produces a horizontal forwards thrust of 3200 N and a drag force of 2400 N opposes the movement.
What is the size of the resultant horizontal force acting on the aeroplane?

Which of the following is a statement of Newton’s Second Law of motion, using standard symbols?

car A: driving force = 500 N, air resistance = 300 N, friction = 200 N

car B: driving force = 600 N, air resistance = 300 N, friction = 200 N

car C: driving force = 700 N, air resistance = 300 N, friction = 300 N

car D: driving force = 800 N, air resistance = 300 N, friction = 400 N

Car E: driving force = 900 N, air resistance = 450 N, friction = 450 N

Five cars, A, B, C, D and E, travel along a straight road. There are three forces acting on each car, the values of which are listed below.
Which of the cars are not accelerating?

What sized resultant force is needed to cause a lorry of mass 3000 kg to accelerate at 0.3 m/s$$^2$$?

Calculate the acceleration of a skydiver of mass 70 kg with a weight of 700 N and a drag force of 490 N acting on them. You do not need to give the unit.

Starter Quiz

Which of the following forces acts on all objects near Earth surface?