Question

The coefficient of kinetic friction between a couch and the floor is .81 if the couch has a mass of 71 kilograms and you push it with a force of 650 newtons what is the net force on the couch as it slides

Answer 1

Hi there!

The equation for the kinetic friction force is:

$F_{kf} = \mu mg$

We can begin by doing a summation of forces acting on the couch where a positive force is in the direction of the couch's acceleration, or in the direction of the push.

Thus:

$\Sigma F = F_A - F_{kf}$

Now, plug in the values:

$F_{net}= 650 - (.81 * 9.8 * 71) = \boxed{86.4 N}$