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 `6` `ms^-2`?

Answer 1

`F=F_"frict"+F_"accel"=196+30=226` `N`

Explanation:

The total force required will be given by `F=F_"frict"+F_"accel"` - the sum of the force required to overcome friction and the force required to accelerate the mass.

The frictional force is given by:

`F_"frict"=muF_"norm"` where the normal force `F_"norm"=mg`

So the friction force is `F_"frict"=mumg=4xx5xx9.8=196` `N`

To accelerate a mass the force given by Newton's Second Law is:

`F_"accel"=ma=5xx6=30` `N`

Then:

`F=F_"frict"+F_"accel"=196+30=226` `N`