Superman is flying 54.5 m/s when he sees
a train about to fall into a river 850 m
away. He must reach the train in 4.22 s.
What acceleration does he need?
(Unit = m/s^2)

Why do electron microscopes have higher resolving power than light microscopes?

Aball with a mass of 275 g is dropped from rest, hits the floor and rebounds upward. if the ball hits the floor with a speed of 2.40 m/s and rebounds with a speed of 1.70 m/s, determine the following. (a) magnitude of the change in the ball's momentum (let up be in the positive direction.)

Abowling ball rolling down the lane toward the pins has gravitational potential energy. a. no b. a lot of c. a little