Question

If a `2 kg` object is constantly accelerated from `0m/s` to `15 m/s` over `6s`, how much power musy be applied at `t= 2`?

Answer 1

The power is `=25W`

Explanation:

The acceleration is

`a=(v-u)/t=(15-0)/6=15/6=2.5ms^-2`

According to Newton's Second Law,

The force is `F=ma=2*2.5=5N`

The speed at `t=2s` is obtained from the equation

`v=u+at=0+2.5*2=5ms^-1`

The power is

`P=Fv=5*5=25W`