four students are moving 80 N boxes from the floor to a shelf 4 meters high. Student A moves 8 boxes in 10 minutes. Student B moves 6 boxes in 8 minutes. Student C moves 6 boxes in 4 minutes and student D moves 4 boxes in 2 minutes. Which student does the most work?

Suppose a comet has an orbital period of 309.1 years around the sun. what is it’s average distance from the sun?

The man of mass m1 and the woman of mass m2 are standing on opposite ends of the platform of mass m0 which moves with negligible friction and is initially at rest with s = 0. the man and woman begin to approach each other. derive an expression for the displacement s of the platform when the two meet in terms of the displacement x1 of the man relative to the platform.

Greg drew a diagram to compare two of the fundamental forces. which labels belong in the areas marked x, y and z? gravitational force electromagnetic force x. attractive y repulsive z: infinite range x: infinite range y attractive z. repulsive x. always attractive y: infinite range z: attractive or repulsive x. attractive or repulsive y infinite range z: always attractive