Question

An object with a mass of `2 kg` is on a surface with a kinetic friction coefficient of `7`. How much force is necessary to accelerate the object horizontally at `6 m/s^2`?

Answer 1

I found: `F=149.2N`

Explanation:

Kinetic Friction is given as:
`f_k=mu_k*N`
Where:
`mu_k=`kinetic friction coefficient`=7`
`N=`Normal Reaction (in this case of horizontal movement)`="weight"=mg`
with:
`m=2kg`
`g=9.8m/s^2`

To produce an acceleration `a=6m/s^2` we need a force `F` to overcome friction that, according to Newton's Second Law, will be given as:
`F-f_k=ma`
`F=f_k+ma`
`F=mu_k*mg+ma`
`F=(7*2*9.8)+(2*6)=149.2N`