Question

Josh is doing sit-ups at a speed of 5 sit-ups per 7 seconds. (First find this speed). Three minutes (180 seconds) later, he is doing sit-ups at a rate of 7 sit-ups per 8 seconds (Second find this speed). What is Josh's acceleration?

Answer 1

9.1*10^-4 sit-ups per square second

Explanation:

Given data

Initial speed= 5/7 = 0.71 sit-ups per second

Time interval= 180 seconds

Final speed= 7/8 = 0.875 sit-ups per second

Hence the acceleration is given as

a= v-u/t

a= (0.875- 0.71)/180

a= 0.165/180

a=0.00091666666

a= 9.1*10^-4 sit-ups per square second