Questions Correction 2023

Question 1

The black coloured flask will emit more infrared radiation than the silver coloured flask during 10 minutes of cooling
Describe a method to test this hypothesis

Answer 1

1) Heat the water using the kettle and add an equal volume of water to each flask and insert a thermometer into each flask
2) Record initial temperature from both flasks and place IR detector near each flask, keep the distance between the IR detector and the flask the same each time
3) Record initial reading from IR detectors
4) Start a stop clock and record temperature after 10 minutes
5) Calculate the change in temperature and compare results to test hypothesis

Question 3

Examples of a contact force

Answer 3

Tension
Upthrust

Question 4

How could the driver increase the moment about the pivot without increasing the size of the force

Answer 4

Apply force further away from the pivot

Question 5

Explain why the distraction will increase the stopping distance

Answer 5

Stopping distance includes thinking distance
There is an additional time before the driver applies the brakes
So the thinking distance will increase

Question 6

Explain why the temperature of the brakes increases as they are used

Answer 6

Work is done due to friction
Causing an increase in the internal energy

Question 7

Closed system definition

Answer 7

The total amount of energy remains constant

Question 8

Explain how the flexible bumper reduces the risk of injury to the people in the bumper car during the collision

Answer 8

Increases the time taken for the collision to occur
So the rate of change of momentum decreases
Reducing the force

Question 9

Explain the effect of the Earths gravitational force on the motion of the Hubble Space Telescope

Answer 9

Gravitational force causes the Hubble Space Telescope to accelerate towards the Earth
This changes the direction of motion but not the speed
So changes the velocity of the Hubble Space telescope

Question 10

Reflection from a smooth surface

Answer 10

Specular reflection

Question 11

What type of error caused the variation in results for the angle of reflection

Answer 11

Random error
The students eye might not be in the same position each time

Question 12

Why is an IRON core used

Answer 12

It is easily magnetised

Question 13

Explain why a direct current is induced in the coil

Answer 13

The coil cuts the magnetic field lines
So a potential difference is induced
There is a complete circuit so a current is induced
As each half-revolution the two ends of the coil swap from one brush to the other
So the direction of current does not reverse every half rotation

Question 14

Explain why the dynamo because much easier to turn

Answer 14

There is no induced current
So no magnetic field
To oppose the movement of the coil