Evaluate — 2 marks
A car manufacturer is testing two different braking systems for their new vehicle. System A applies a constant braking force of 5000 N, while System B applies a constant braking force of 8000 N. Both systems are tested on identical cars with a mass of 1000 kg, all travelling at the same initial speed.
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Calculate the deceleration produced by System A using Newton's Second Law (F = ma).
[1 mark]
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Evaluate which braking system would be more effective at stopping the car quickly. Justify your answer using Newton's Second Law.
[1 mark]
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Suggest — 5 marks
A stunt driver is planning a scene where a car must accelerate rapidly from rest and then brake suddenly to avoid an obstacle. The car has a mass of 1200 kg. During acceleration, the engine provides a driving force, and during braking, friction acts on the wheels. The driver is concerned about passenger safety and the structural integrity of the vehicle during both phases of motion.
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During the acceleration phase, the driving force from the engine is 4800 N and the resistance forces total 1200 N. Calculate the acceleration of the car.
[2 marks]
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Suggest why the passengers experience a backward force during the acceleration phase, referring to Newton's laws in your answer.
[2 marks]
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The car reaches a velocity of 20 m/s before braking. The braking force is 6000 N. Suggest what additional safety consideration the stunt coordinator should make regarding the magnitude of the braking force and explain your reasoning using Newton's second law.
[1 mark]
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Define — 4 marks
A delivery driver is transporting a parcel in the back of a van. When the van suddenly brakes, the parcel slides forwards across the floor, even though the driver applied the brakes to slow the van down.
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Define what is meant by inertia.
[1 mark]
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Define Newton's first law of motion.
[2 marks]
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Using Newton's first law, explain why the parcel slides forwards when the van brakes suddenly.
[1 mark]
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Show — 4 marks
A delivery driver pushes a 25 kg box across a warehouse floor. The box accelerates from rest to 2 m/s in 4 seconds. The driver applies a constant horizontal force, and friction acts against the motion.
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Calculate the acceleration of the box.
[1 mark]
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Show that the resultant force acting on the box is 12.5 N. (You may assume friction is negligible.)
[2 marks]
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In reality, friction acts on the box with a force of 37.5 N. Show that the driver must apply a force of 50 N to achieve the same acceleration as calculated in part (a).
[1 mark]
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State — 4 marks
A skydiver jumps from an aircraft at high altitude. During the initial phase of the jump, the skydiver accelerates downwards. After several seconds, the skydiver reaches terminal velocity where the downward acceleration becomes zero. Later, the skydiver deploys their parachute, causing a large upward force that rapidly reduces their speed.
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State Newton's second law of motion.
[1 mark]
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State the condition that must be satisfied for the skydiver to be in equilibrium (zero acceleration) at terminal velocity, in terms of the forces acting on the skydiver.
[1 mark]
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State which of Newton's three laws of motion explains why the skydiver experiences a reaction force from the air resistance acting downwards on the atmosphere.
[1 mark]
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State the relationship between the net force on the skydiver and their acceleration immediately after the parachute deploys, when the upward force from the parachute is greater than the skydiver's weight.
[1 mark]
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GCSE Perfect