An object with a mass of 12 kg is on a surface with a kinetic friction coefficient of 1. How much force is necessary to accelerate the object horizontally at 7 ms2?

1 Answer
Feb 13, 2016

The total force is composed of two pieces: the force required to accelerate the mass and the force required to overcome friction. F=ma+μmg=127+1129.8=201.6 N.

Explanation:

The total force is made up of two different forces.

If there were no friction, the force required to accelerate a mass of 12 kg at an acceleration of 7 ms2 is given by Newton's Second Law :

F=ma=127=84 N

The second part is the frictional force:

Ff=μFN where μ is the frictional coefficient and FN is the normal force, which in turn is mg, the mass times the acceleration due to gravity.

Ff=μmg=1129.8=117.6 N

To find the total force, just add these two forces:

F=ma+μmg=127+1129.8=201.6 N.