In a ruler-drop test, a ruler falls 0.20 m from rest before it is caught. The acceleration of the ruler is 10 m/s2.
Use the equation:
(final velocity)2−(initial velocity)2=2×acceleration×distance(\text{final velocity})^2 - (\text{initial velocity})^2 = 2 \times \text{acceleration} \times \text{distance}(final velocity)2−(initial velocity)2=2×acceleration×distance
What is the reaction time of the person catching the ruler?
0.020 s0.020\ \text{s}0.020 s
0.040 s0.040\ \text{s}0.040 s
0.20 s0.20\ \text{s}0.20 s
2.0 s2.0\ \text{s}2.0 s
50 exam-style questions on OCR GCSE Physics 8.1 Physics on the move, covering 8.1.1 Typical everyday speeds, 8.1.2 Typical everyday accelerations, 8.1.3 Ratios, units and rates on the road, 8.1.4 Human reaction times, 8.1.5 Factors affecting stopping distance, 8.1.6 Stopping distances at different speeds, 8.1.7 Dangers of large decelerations, 8.1.8 Estimating forces in road situations, and 8.1.9 Estimating the effects of large accelerations. Each one has a worked solution and a mark scheme showing where the marks go.