Forces (OCR GCSE Physics A (Gateway)): Exam Questions

Exam code: J249

53 mins15 questions
1a
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1 mark

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A model aircraft is flying through air. The diagram shows the forces acting on the model aircraft. The weight of the model aircraft is 15.0 N.

Diagram of an aeroplane in motion with arrows showing forces: 19.0 N left, 11.0 N right, and 15.0 N both upwards and downwards. Direction of motion is left.

Determine the size and direction of the resultant horizontal force acting on the model aircraft. Give your answer in newtons.

1b
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2 marks

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Describe the properties of the motion of the model aircraft.

1c
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1 mark

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The horizontal forces acting on the model aircraft become balanced.

Suggest how the horizontal forces acting on the model aircraft have changed.

1d
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2 marks

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Another aeroplane takes off and the engines quickly exert maximum thrust, which is initially greater than air resistance.

A student attempts to describe this motion, complete their sentences:

Initially, the aeroplane has a very large ................... , but this eventually drops to 0 m/s2.

At this point, air resistance is equal to thrust and the aeroplane has reached ................................ .

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2a1 mark

Objects can interact in many ways. Pairs of forces arise when objects interact.

Write down one type of force involved when objects interact.

2b4 marks

A book rests on a table.

Draw a free body force diagram to show the forces acting on the book.

Use arrows to represent the forces.

2c2 marks

A teacher uses an air-track for motion experiments. Using the air-track means that there is no friction between the glider and the air-track.

The teacher places the glider on the horizontal air-track and gives it a small push to start it moving.

Explain the motion of the glider.

2d5 marks

A presenter on a car TV programme says: “The car maker has reduced the mass of this car and it now has better acceleration.”

i) Explain why the presenter is correct.

[2]

ii) A car accelerates from 5 m/s to 25 m/s in 4 seconds. Calculate the acceleration of the car.

Use the equation: Acceleration = Change in speed ÷ Time taken

Answer = ............................................ m/s2 [3]

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3a
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1 mark

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A car travels around a circular track at a constant speed.

Explain why it is incorrect to describe the circular motion as having a constant velocity.

3b
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2 marks

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A force is required for the car to maintain the circular motion.

Explain why a force is required.

3c
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1 mark

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State the direction in which the force acts for objects in circular motion.

3d
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1 mark

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State the name of this force for the car on the track.

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4a
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4 marks

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Three parachutes are used to slow down a spacecraft as it falls through the atmosphere. 

The spacecraft falls at a constant velocity.

State the name of this constant velocity and explain why this velocity stays at a constant value.

4b
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2 marks

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Draw a free body diagram for the spacecraft at its terminal velocity.

4c
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2 marks

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The same spacecraft falls through the atmosphere in a test run, but only two of its parachutes are working.

Explain how the constant velocity reached by this spacecraft compares with the constant velocity of the spacecraft in part (a).

4d1 mark

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When the spacecraft is at a velocity less than its terminal velocity, a strong wind blows to the right.

State the direction of the resultant force on the spacecraft.

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5a3 marks

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A free-fall skydiver falls from a plane and reaches terminal velocity after 15 seconds.

Look at the graph of her motion.

q24-paper3-specimen-ocr-gcse-physics

Use the graph to find the acceleration at 5 seconds.

Answer = ......................... m/s2

5b2 marks

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Use the graph to find the distance travelled between 0 and 2.5 seconds.

Answer= ......................... m

5c6 marks

Higher Tier Only

A skydiver jumps from an aeroplane, falls towards the ground, opens her parachute and falls safely to Earth.

Look at the graph of the velocity of the skydiver as she falls.

q24c-paper3-specimen-ocr-gcse-physics

Look at these regions of the graph:

  • x

  • y

Use ideas about forces to explain the motion during x and y.

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