AQA GCSE Physics (8463), Higher tier · Forces › Forces and their interactions
Practise Contact and non-contact forces. 11 exam-style questions on this subtopic, at up to four difficulty levels, with full mark schemes and a progress tracker. Free, no account needed.
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Name two other non-contact forces.
Gravitational force (weight) and electrostatic force.
Name one contact force and one non-contact force that act on the kite-surfer.
Contact: tension in the lines. Non-contact: weight (gravitational force).
State whether friction is a contact force or a non-contact force.
Contact.
A maglev (magnetic levitation) train uses magnets to float just above its track, without touching it. Magnets in the track also drive the train forwards, again without any contact between the train and the track. Name the force that holds the train up.
Magnetic force.
A student rubs a plastic comb on their hair. The student then holds the comb close to, but not touching, small pieces of paper on a table. The pieces of paper jump upwards and stick to the comb. Name the non-contact force responsible for this effect.
Electrostatic force.
Sample questions
Written for this site in the style of AQA exam questions. They are not taken from real past papers.
Question 1Easy6 marks
(a) Which of these forces is a non-contact force? Tick (✓) one box.[1]
Air resistance
Friction
Magnetic force
Tension
(b) Name two other non-contact forces.[2]
(c) Describe the difference between a contact force and a non-contact force.[2]
(d) Force is a vector quantity. What does this mean?[1]
Show the answer and mark scheme
(a)Answer: Magnetic force
(b)Answer: Gravitational force (weight) and electrostatic force.
gravitational force / weight / gravity
electrostatic force
(c)Answer: Contact forces act between objects that touch; non-contact forces act between objects that are separated.
contact force: the objects are (physically) touching
non-contact force: the objects are (physically) separated / not touching
(d)Answer: It has magnitude and direction.
force has magnitude (size) and direction
Question 2Medium6 marks
A kite-surfer stands on a board and is pulled across the sea by a large kite. The kite is attached to the kite-surfer by lines.
(a) Name one contact force and one non-contact force that act on the kite-surfer.[2]
(b) The weight of the kite-surfer is caused by an interaction between the kite-surfer and the Earth. Describe the force that the kite-surfer exerts on the Earth as a result of this interaction.[2]
(c) The kite lines exert a force of 450 N on the kite-surfer, pulling towards the kite. Give the size and direction of the force that the kite-surfer exerts on the kite lines.[2]
Show the answer and mark scheme
(a)Answer: Contact: tension in the lines. Non-contact: weight (gravitational force).
contact: tension (in the lines) / air resistance / drag / normal contact force (from the board) / friction (from the board)
non-contact: weight / gravitational force
(b)Answer: A gravitational force on the Earth, equal in size to the kite-surfer’s weight and directed upwards towards the kite-surfer.
a (non-contact) gravitational force on the Earth
equal in size to the kite-surfer’s weight and in the opposite direction / upwards (towards the kite-surfer)
(c)Answer: 450 N, directed away from the kite.
450 (N)
away from the kite / in the opposite direction (to the force on the kite-surfer)
Question 3Hard6 marks
A student rubs a plastic comb on their hair. The student then holds the comb close to, but not touching, small pieces of paper on a table. The pieces of paper jump upwards and stick to the comb.
(a) Name the non-contact force responsible for this effect.[1]
(b) Explain, in terms of forces, why the pieces of paper jump upwards towards the comb.[3]
(c) A student says: ‘The paper must be attracted because the comb actually touches it through the air.’ Explain why this statement is incorrect.[2]
Show the answer and mark scheme
(a)Answer: Electrostatic force.
electrostatic force
(b)Answer: The charged comb attracts the paper electrostatically; once this force exceeds the paper's weight, the resultant force is upwards and the paper accelerates up.
rubbing the comb on hair gives the comb an electric charge
the charged comb exerts an attractive electrostatic force on the paper
once this upward force becomes bigger than the weight of the paper, there is a resultant force upwards, so the paper accelerates upwards off the table
(c)Answer: The comb and paper are separated by air; a non-contact force acts across that gap without the objects touching.
the comb and the paper are not touching — they are separated by a gap of air
a non-contact force, by definition, can act across a gap without the objects touching, which is exactly what is happening here