A road-safety trial compares two drivers. Driver A is alert on worn tyres; driver B is tired on new tyres. Both drive at the same speed on the same road. Only their final stopping distances are recorded.
Evaluate whether this trial can show how tiredness affects stopping distance. Explain a better investigation that avoids driving while tired.
[6 marks]
6 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
Students want to compare wave speeds on the same stretched string at two different tensions. They have a vibration generator, signal generator, pulley, masses, metre rule, a high-speed camera with a short exposure and an absorbing termination that suppresses reflected waves before the pulley. The camera resolves individual travelling-wave crests.
Plan a valid comparison using measurements of frequency and wavelength.
[6 marks]
6 marksHigher
Spec and skills
Original practice question
Answer and supported method checks
A town receives electricity from distant power stations through the National Grid. A pupil proposes removing all transformers because transformers do not create energy.
Evaluate the proposal by explaining the roles of the transformers and the cables.
[6 marks]
5 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
An imaging leaflet gives typical effective doses: one chest X-ray 0.020 mSv and one CT examination 4.0 mSv. These values are supplied; you do not need to recall dose units.
.1
Calculate the number of chest X-rays giving the same listed total dose as one CT examination.
[2 marks]
.2
Explain why the dose comparison alone cannot decide whether a patient should have the CT examination.
[3 marks]
6 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
A worker is near a sealed radioactive source for a short time. Another worker has radioactive dust on a glove. A supervisor recommends tongs, shielding and careful removal of the contaminated glove.
Explain the different hazards and how the precautions reduce them.
