Systems Acting at Distance Practice Test

A magnet attracts a steel paper clip from a distance of $5,\text{cm}$. The clip starts at rest, not touching the magnet, and then moves toward the magnet through the air gap. Which statement is correct about the work done by the magnetic force and the clip’s energy?

A $1,\text{kg}$ object is lifted straight up at constant speed from $h=0,\text{m}$ to $h=3,\text{m}$. Gravity pulls downward during the entire motion even though the object is not touching Earth. What is the work done by gravity on the object during the lift? (Use $g\approx 10,\text{m/s}^2$.)