Question

An object with a mass of `2 kg` is on a surface with a kinetic friction coefficient of `3`. How much force is necessary to accelerate the object horizontally at `6 m/s^2`?

Answer 1

`70.8 N`

Explanation:

Here,if we have to move the object against frictional force with acceleration,then frictional force must be exerting its maximum value against the motion.

Maximum frictional `f` force that can act here is `muN=mug=3*2g=6*9.8=58.8N` (where, `mu` is the coefficient of kinetic friction)

So,if we need to apply force `F` to accelerate it at an acceleration of `a`,

Then we can write,acceleartion which is due to the net force acting is,

`F-f=ma`

or, `F-58.8=2*6`

so, `F=70.8 N`