A man pushes a lawn mower on a level lawn with a force of 210 N. If 48% of this force is directed downward, how much work is done by the man in pushing the mower 4.5 m?

Answer 1

The total force of 210 N is directed at some angle downward from the horizontal. Forty eight percent of this force is directed downward; so, the downward force is 0.48 x 210 = 100.8 N. To calculate the work done, we need to determine the horizontal component of the applied force.

This can be calculated using a rearranged pythagorean theorem with the total force being the hypotenuse of a right triangle consisting of the vertical and horizontal components of the force.

Horizontal component = square root (total force² - vertical component²) =

210² - 100.8² = 184 N

Work is horizontal component x 4.5 m = 184 N x 4.5 m = 828 Joules