FORCES AND SHAPE
4 marks · NormalA football is resting on a field. A player kicks the football, making it move, and it eventually comes to a stop.
State two different effects that a force can have on an object. For each effect, give an example involving the football.
Explain which force causes the football to slow down and eventually stop after being kicked.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
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(a) Change speed (e.g. kicking makes football move), change direction (e.g. bouncing off another player or object), or change shape (deformation as it's kicked)
(b) Friction (and/or air resistance) acts in the opposite direction to the football's motion, causing it to slow down and eventually stop.
Common mistakes: Confusing air resistance and friction without explanation; Giving 'move' as an effect rather than 'change speed' or 'direction'
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · States an effect of force (change speed, direction, or shape) with a football example
B2 (a) · 1 mark · States a second effect with a relevant football example
B3 (b) · 1 mark · Identifies friction/air resistance as the force causing the football to stop
B4 (b) · 1 mark · Explains that this force acts in the opposite direction to motion, causing deceleration and stopping
Worked solution
a) Two effects of a force are: - Change in speed: when the player kicks the football, it begins to move (speed increases). - Change in direction: if the ball hits another object, it may change direction.
b) Friction (and air resistance) acts in the opposite direction to the football's movement. This force opposes the motion and gradually reduces the ball's speed until it stops.