Question

What is the average speed of an object that is moving at `9 m/s` at `t=0` and accelerates at a rate of `a(t) =5-2t` on `t in [0,5]`?

Answer 1

Average speed is the mean of initial velocity and final velocity.

to solve this question we need to take out final velocity (`v`) and initial velocity(`u`) is already proided.

so lets proceed.

`a(t)=5-2t`
therefore accereleration at 5 seconds is -5`m/s^2`.This is derieved by puting t=5 in the above equation/function.

`a=v/t-u/t`

by putting values this we get `v=-12m/s`

so `u=9m/s` and `v=-12m/s`

`V_av= (u+v)/2`
=`-1.5m/s` .

I haven't showed the actual mathematics calculation as i hope you can easily make it,she see the procedure.