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]
6 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
A detector registers 96 counts per minute of background radiation. With a source present it registers 896 counts per minute initially and 496 counts per minute after 12 minutes.
.1
Calculate the initial corrected detected count rate in min−1 (counts per minute).
[2 marks]
.2
Determine the half-life in minutes.
[2 marks]
.3
Explain why the background must be subtracted before comparing the rates.
[2 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]
5 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
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]
7 marksHigher
Spec and skills
Original practice question
Answer and supported method checks
A spring stores 0.72 J when compressed by 0.060 m. It obeys Hooke's law throughout this compression. It launches an initially stationary 0.090 kg toy horizontally; 25% of the stored energy is dissipated.
.1
Calculate the spring constant.
[2 marks]
.2
Calculate the toy's speed when it leaves the spring.
[3 marks]
.3
Explain why the speed cannot be found by treating the dissipated energy as destroyed.
