Question

An object with a mass of `5 kg` is on a surface with a kinetic friction coefficient of `4`. How much force is necessary to accelerate the object horizontally at `3 m/s^2`?

Answer 1

The force is `=211N`

Explanation:

The normal reaction is `N=mg=5g`

The frictional force

`F_f=mu_k.N`

`F_f=4*5g=20g`

Let the force necessary to accelerate the object be `F`

Then,

`F-F_f=m*a`

`F=F_f+m*a`

`=20g+5*3`

`=211 N`