Answers to End-of-chapter questions
3 Dynamics – explaining motion
1 a 6440 ≈ 6400 N
b 656 ≈ 660 kg
2 a 112 N
b 388 N
c 5.54 m s−2
3 a At first the only force is the weight but as its
speed increases viscous drag increases. When
viscous drag equals weight the acceleration is
zero and the speed is constant.
b Put rubber bands around the cylinder the
same vertical distance apart along the cylinder.
Time the ball between the bands. When
terminal velocity is reached the time taken
between successive bands will be constant.
4 a 6 × 10−4 m s−1
b 2 × 10−3 m s−1
c 2 × 10−3 m s−1
5 a i The Earth, ii upwards, iii gravitational force
b i The Earth or the ground under the man,
ii downwards, iii contact force
AS and A Level Physics © Cambridge University Press
Chapter 3: Answers to End-of-chapter
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