Evan and Harper were planning to run on a circular track with a circumference of 1000 m. Both of them started jogging together at the same start point and moved round the track in a clockwise direction at uniform speeds. Evan completed a full round in 50 s. Harper completed a full round in 40 s.
- How long would it take for Harper to overtake Evan for the first time?
- How far was Harper ahead of Evan after 25 s?
(a)
LCM of 40 and 50 is 200.
Time taken for Harper to overtake Evan
= 200 s
(b)
Harper's speed
= 1000 ÷ 40
= 25 m/s
Evan's speed
= 1000 ÷ 50
= 20 m/s
Difference in speed
= 25 - 20
= 5 m/s
Distance Evan was behind Harper after 25s
= 25 x 5
= 125 m
Answer(s): (a) 200s; (b) 125 m