Question

Stephanie starts out on run covering 100 m in 10 minutes. She then accelerates to a speed of 15 m/min in 10 seconds. What is her acceleration?

Answer 1

30 m/min² (= 0.0833 m/s²)

Explanation:

Initially,

Distance ran = 100 m

Time taken = 10 min

Average speed = Distance ran ÷ Time taken

= 100 ÷ 10

= 10 m/min

Hence here initial speed = 10 m/min

Given that her final speed was 15 m/min

her change in speed = 15 - 10 = 5 m / min

We are also given that this change in speed took 10 seconds = 1/6 min

Recall that by definition, acieration = rate of change of speed

= change in speed ÷ time taken for change

= 5 m/min ÷ (1/6) min

= 30 m/min² (= 0.0833 m/s²)