Question

Explain please with details ?

Answer 1

`A. 7.82m`

Explanation:

Suppose,here its mass is `m`

So,on application of constant force of `F`,constant acceleration will be `F/m`

Now,if after pushing by distance `s` it acquires a velocity of `v` then,

`v^2 =2as` (using, `v^2=u^2+2as`,here, `u=0` as started from rest)

So, `v^2 =(2Fs)/m`

Now,after pushing for distance `s` if its kinetic energy will be `1/2mv^2=1/2 m (2Fs)/m=Fs`

Given, `1/2 mv^2=352J` and `F=45N`

So,`Fs =352`

Or, `s=352/45=7.82m`

Answer 2

`a. 7.82m`

Explanation:

ALTERNATIVELY,

Here work done by the force `F` is stored as kinetic energy of the mass.

So,work done by `F` in displacing it by `s` is `Fs=352`

So, `s=352/45=7.82` (given, `F=45N`)