I need help with these two.

1. A horizontal force pulls a 20-kg box across the floor with constant speed. μs is 0.60, how much work does F do in moving the cart 3.0 m?

2. A 400 lb load of bricks is to be lifted to the top of a scaffold 30 feet high. How much work to lift it?

1 answer

1. if μs is static coefficent, it wont help here, you need μk
work= μk*20*g*3

2. work=mgh

here, mg=400 lbs
work=400*30 ft-lbs