A 40N force pulls a 4kg block a horizontal distance of 8m The rope makes an angle of 35 degrees with the floor and the kinetic friction is equal to 0.2 What is the work done?

Answer 1

The horizontal component of 40N at 35° is 40 cos(35°) = 32.7661 N (rounded)

The friction is irrelevant, and so is the mass of the block. I'm not sure that all the

given numbers even add up ... a 4Kg block sitting on a friction coefficient of 0.2

might not need 32.7661 N to slide it along the floor, or it might need more than that.

We don't care. All we need in order to calculate the work is the force and the distance.

Force = 32.7661 N

Distance = 8 m

Work = (force) x (distance) = 262.1287 Joules(rounded)

The vertical component of the 40N just goes along for the ride, and it doesn't do

any work. We know that because the front of the block doesn't lift up off the floor,

so the vertical component doesn't move through any vertical distance.