A lifting device measures the weight of several masses on a planet. Results are 6 N for 2 kg, 15 N for 5 kg and 24 N for 8 kg. Measurements pass through the origin on a weight-mass graph.
01234567891051015202530Mass (kg)Weight (N)
.1
Calculate the gravitational field strength on the planet.
[2 marks]
.2
Calculate the mass of an object that weighs 42 N there.
[2 marks]
.3
Explain why using several masses supports the result more than using one reading.
[2 marks]
5 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
A student measures the resistance of 0.20 m, 0.40 m and 0.60 m of one uniform wire. Values are 1.6 Ω, 3.2 Ω and 5.6 Ω. The 0.60 m measurement is made after current has flowed for several minutes.
.1
Use the first two results to calculate the expected resistance of 0.60 m of wire at the original temperature.
[2 marks]
.2
Evaluate the final result and suggest how to improve the investigation.
[3 marks]
6 marksHigher
Spec and skills
Original practice question
Answer and supported method checks
A simple motor has a rectangular current-carrying coil between two magnet poles. A student suggests increasing current, using stronger magnets and making the active sides parallel to the magnetic field to increase rotation.
Evaluate these suggestions using the motor effect. Explain the role of the two sides of the coil.
[6 marks]
4 marksHigher
Spec and skills
Original practice question
Answer and supported method checks
A heater supplies 12000 J to 0.10 kg of ice already at 0 °C. The specific latent heat of fusion is 334000 J/kg. Assume no energy reaches the surroundings.
.1
Calculate the mass of ice that melts.
[2 marks]
.2
Evaluate the statement that the final temperature must be above 0 °C because energy was supplied.
[2 marks]
4 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
A light pulse and a sound pulse leave the same device simultaneously. The observer is 680 m away. Take sound speed as 340 m/s and light speed as 3.0×108 m/s.
.1
Calculate the travel time of the sound.
[2 marks]
.2
Explain why timing from the visible flash to the sound is a reasonable way to measure the sound travel time here.
