Question

The velocity of an object with a mass of `3 kg` is given by `v(t)= 3 t^2 - 5 t`. What is the impulse applied to the object at `t= 2`?

Answer 1

`6"N.s"`

Explanation:

The impulse is the average force x time

The average force id given by:

`F_((ave))=(mDeltav)/t`

So the impulse = `mDeltav/cancel(t)xxcancel(t)`

`=mDeltav`

`v(t)=3t^2-5`

So after 2s:

`v=3xx2^2-5xx2=2"m/s"`

Assuming the impulse is over a period of 2s then `Deltav=2"m/s"`

`:.` Impulse`=3xx2=6"N.s"`