Circular Motion (Edexcel A Level Physics)

Exam Questions

41 mins5 questions
1a
Sme Calculator
3 marks

The photograph shows a model racing car set. The curved parts of the track are semicircular. The car makes electrical contact with the track using metal brushes underneath the car.

q13-nov-2020-9ph0-01-edexcel-as-a-level-phy

There is a maximum speed for the car to stay on the curved part of the track.
Explain why the car will slip off the curved part of the track if the car exceeds the maximum speed.

1b
Sme Calculator
4 marks

The following measurements are made for a car starting at rest on a straight piece of track.

   distance travelled = 1.2 m

   time taken = 0.77 s

i)
Show that the final velocity of the car is about 3 m s−1.

Assume the acceleration is constant.

(2)

ii)
The final velocity calculated in (b)(i) is the maximum velocity before the car slips off the track.

Calculate the maximum horizontal force between the curved part of the track and the car.

mass of car = 0.050 kg

radius of curved part of track = 0.042 m

(2)




Maximum horizontal force = ......................................................

1c
Sme Calculator
3 marks

The cars are controlled separately and so can be raced, with one car on the inner lane and the other on the outer lane. The cars are identical. Each car is raced at its highest speed for that lane.

Explain why the outcome of the race is difficult to predict.

Did this page help you?

2a
Sme Calculator
2 marks

The International Space Station (ISS) orbits the Earth with a constant speed v. The orbit is circular and of radius r.

The diagram represents two positions, A and B, of ISS during its orbit.

q11a-nov-2021-9ph0-01-edexcel-as-a-level-phy


Draw a labelled vector diagram, in the space below, of the velocities at the two positions that shows the acceleration is directed towards the centre of the orbit.

2b
Sme Calculator
7 marks
i)
The ISS completes one orbit in 92 minutes.

Calculate the centripetal acceleration of the ISS.
r = 6800 km

(3)

Centripetal acceleration = .......................................................



ii)
Astronauts in the ISS are often described as being “weightless”.
Discuss whether the astronauts are “weightless” when they are orbiting the Earth in the ISS.

(4)

Did this page help you?

3a
Sme Calculator
5 marks

A centrifuge is a machine which rotates.

A particle in a centrifuge moves in a circle of radius r, centre O, with a constant speed v.

The diagram represents two positions of the particle.

q17a-june-2018-9ph0-01-edexcel-as-a-level-phy

Derive the equation for centripetal acceleration a equals v squared over rby considering the velocity at these two positions.

Your answer should include a vector diagram.

3b
Sme Calculator
6 marks

The United States’ space agency, NASA, uses a centrifuge to test whether equipment will operate when experiencing large forces. The equipment to be tested is attached to the end of the frame of the centrifuge, which rotates around a vertical axis at its centre.

q17b-june-2018-9ph0-01-edexcel-as-a-level-phy

The centrifuge rotates at 50 revolutions per minute with a radius of 8.8 m.

i)
Show that the angular velocity of the centrifuge is about 5 rad s–1.

(2)

ii)
Explain how the centrifuge applies large forces to the equipment under test.

(2)

iii)
The NASA website says the centrifuge can be used to test whether the equipment can withstand accelerations of up to about 25g.

Deduce whether this claim is correct.

(2)

Did this page help you?

1a
Sme Calculator
6 marks

The Enterprise is an amusement park ride. Riders sit in cars that are made to rotate in a vertical circle.

The ride starts by moving in a horizontal circle. The speed of rotation increases, and the frame tilts until the ride is rotating vertically as shown.

q6-nov-2021-9ph0-03-edexcel-as-a-level-phy

The photograph below shows riders at the top of the vertical circle. The riders are in contact with their seats at all times during the ride.

q6-1-nov-2021-9ph0-03-edexcel-as-a-level-phy

The diagram shows the weight W of a rider and the push P from the seat on the rider at the top and bottom of the circular path.

q6-2-nov-2021-9ph0-03-edexcel-as-a-level-phy

The rider moves from the bottom to the top of the circular path.

Explain how the apparent weight experienced by the rider would change.

1b
Sme Calculator
4 marks

On the website of the amusement park it states


“The ride is perfectly safe without the need for safety harnesses for the riders. Centrifugal force ensures that the riders remain in their seats at all stages in the ride.”

Assess the validity of this statement.

Did this page help you?