Units (Forces and Motion)
4 marks · NormalA cyclist travels 200 metres in 25 seconds.
What is the average speed of the cyclist? Give the correct unit and symbol.
Name the SI base unit for time, including its symbol.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(a) 8 m/s · must show correct calculation of speed, correct unit (m/s) and symbol
(b) second (s) · must show unit: second, symbol: s
Common mistakes: using km/h instead of m/s; using minutes/hours for time
Show mark scheme and worked solution
Marking points
M1 (a) · 1 mark · Correct use of speed = distance/time. (follow-through)
A1 (a) · 1 mark · Calculation: 200/25 = 8. (follow-through)
B1 (a) · 1 mark · Correct SI unit/symbol for speed: m/s.
B2 (b) · 1 mark · Correct SI base unit and symbol for time: second (s).
Worked solution
a) Average speed = distance ÷ time = 200 m ÷ 25 s = 8 m/s.
b) The SI base unit for time is second (s).