Question

What is the average speed of an object that is not moving at `t=0` and accelerates at a rate of `a(t) =10-2t` on `t in [3, 5]`?

Answer 1

`v_a=4`

Explanation:

`v_a=int _3^5 a(t)d t`
`v_a=int _3^5 (10-2t)d t`
`v_a=[10t-t^2]_3^5+C`
`"for t=0 ; v=0; then C=0"`
`v_a= [10*5-5^2]-[10*3-3^2]`
`v_a=(50-25)-(30-9)`
`v_a=25-21`
`v_a=4`