Identical detectors at equal distances from two heated plates record infrared signal after the background reading has been subtracted. Both plates have the same area and temperature. Matt black gives 8.4 units and shiny silver gives 2.1 units.
.1
Calculate how many times larger the black-plate signal is.
[2 marks]
.2
Evaluate whether the measurements support using a shiny surface to reduce thermal radiation losses.
[3 marks]
4 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
An atom absorbs electromagnetic radiation and one electron moves to a higher energy level. Later the electron returns to its original level.
Explain the energy transfers and why the element does not change.
[4 marks]
5 marksHigher
Spec and skills
Original practice question
Answer and supported method checks
In a collision test the total momentum before impact is 0.500 kg m/s. Three repeats give total momentum after impact of 0.492, 0.501 and 0.495 kg m/s, all in the original direction.
.1
Calculate the mean total momentum after impact.
[2 marks]
.2
The uncertainty in the mean is estimated as 0.010 kg m/s. Evaluate whether these results contradict conservation of momentum.
[3 marks]
5 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
A trolley experiment uses a total moving mass of 0.80 kg. Resultant forces 0.40 N, 0.80 N and 1.20 N produce accelerations 0.50, 1.00 and 1.50 m/s².
.1
Calculate the acceleration predicted for a 1.60 N resultant force.
[2 marks]
.2
Evaluate whether the data support the proposed relationship, and identify one way to make the conclusion more reliable.
[3 marks]
6 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
Equal hot-water bottles are wrapped in equal-thickness samples of wool, foam and foil. In 10 minutes their temperature falls are 5 °C, 3 °C and 7 °C respectively. The starting temperatures, water masses and room temperatures are the same.
Evaluate the conclusion that foam is always the best insulator. Include evidence, limitations and an improved comparison.
