Question

If a `2 kg` object is constantly accelerated from `0m/s` to `16 m/s` over `9 s`, how much power musy be applied at `t=7`?

Answer 1

`44.24 W`

Explanation:

acceleration of the object is `16/9 m/s^2` (using `v=u-at`)

hence force acting on it is,`F`=`m*a` or `32/9 N`

velocity of the object at `7` sec is`16/9 * 7` or `112/9` `m/s`

hence,power applied at `7` sec is `F*v` or, `32/9 * 112/9` `W` i.e `44.24 W`