Most of the heat for contact metamorphosisism is supplied by what?

An engine takes in 200 J of heat, expels 40 J of heat, and does 160 J of work. What is the efficiency of the engine? A. 40% B. 60% C. 80% D. 20%

Name 5 spheres of the earth.

You have a mass of 60-kg, and you are facing your friend who has a mass of 100 kg. You skate towards each other fast, and after you collide you both come perfectly to rest.

How does quantum theory explain the working of a photocell? A. Each light wave with a certain minimum energy releases an electron from an atom. B. Each photon of light with energy below a certain value releases an electron from an atom. C.

What is a Rift Valley?

1) What happens when two negatively charged tape strips are placed near each other?

Claudia throws a baseball to her dog. Which free-body diagram shows the baseball when it's flying horizontally in midair? (Assume no air resistance.)

What causes an air conditioned to turn on

A turntable is spinning on a frictionless axle when a ball of putty is dropped onto it from above. The putty sticks to the turntable when it lands. Is angular momentum conserved for the turntable and putty (the system) during this process?

The speedof a boat in still water is v. The boat is to make a round-trip ina river whose current travels at speed u.