Question

A block slides forward 4.73 m while being pulled back by a 39.7 N force at 142° from the direction of motion. How much work does the force do?

Answer 1

Answer:

work done by the force, W = -147.97 J

Given:

displacement of the box, s = 4.73 m

angle between force and displacement, $\theta = 142^{\circ}$

Force, F = 39.7 N

Solution:

Work done by the force can be expressed as the dot product of Force, F and displacement 's' is given by:

W = Fscos$\theta$

W = 39.7$\times 4.73\times cos142^{\circ}$

W = -147.97 J

where negative sign indicates that work is done on the block