If you lift a 80 N book 50 cm off the floor, how much work did you do? 1. 0

2. 4000 J

3. 40 J

4. 1.6 J

A man pushes a couch a distance of 0.75 m. If 450 J of work is done, what is the magnitude of the force applied?

1. 16.9 J

2. 45

3. 1350 J

4. 2700 J

The electric field between square plates of a parallel-plate capacitor has magnitude e. the potential across the plates is maintained with constant voltage by a battery as they are pulled apart to twice their original separation, which is small compared to the dimensions of the plates. the magnitude of the electric field between the plates is now equal to a)e b)e/4 c)e/2 d)4e e)2e

Astudent weighing 700 n climbs at constant speed to the top of an 8 m vertical rope in 10 s. the average power expended by the student to overcome gravity is most nearly

What is the gravitational attraction between a dating couple whose centers of mass are 0.630 m apart if the boy weighs 715 n and the girl weighs 465 n?