In a specific heat capacity investigation, a 0.60 kg block receives 7200 J from a heater. Its temperature rises from 18 °C to 38 °C. A second run with the same block and input energy gives a rise of only 16 °C.
.1
Calculate the specific heat capacity using the first run.
[3 marks]
.2
The student claims that the second run proves the metal has changed. Evaluate the claim and describe one check on the temperature measurement.
[2 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.
[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]
5 marksHigher
Spec and skills
Original practice question
Answer and supported method checks
A simplified early atomic model placed electrons inside a spread-out positive charge. Later scattering evidence supported a small positive nucleus. Further work showed that electrons occupy particular energy levels and that nuclei contain neutrons.
Evaluate the claim that changing the atomic model shows that scientific models are useless.
