Assume the distance axis is linear and da = 10.0m and db = 35.0 m. Estimate the work done by a force F in moving a 2.80 kg object from da to db.

Answer 1

W = Mg * d = 2.80*9.8 * (35-10) = 686 J.

Answer 2

This is sort of a stupid problem. You don't need the mass of the object to solve the problem. If you look at the figure, the force corresponding to 10 m is 150 N and the one corresponding to 35 m is 250 N. Then the work is: W=(35-10)*(150+250)/2 ( this is the area of the trapeze in the diagram). So, W=5000 J