Identify two simple machines in this compound machine.
a. screw, lever
b. screw, incline plane
c. double pulley
d. lever, pulley

Which best describes the first law of thermodynamics as compared to the second law of thermodynamics? a. the first law describes how thermal energy is conserved but not the direction it moves. b. the first law describes the direction thermal energy moves but not how it is conserved. c. the first law describes how thermal energy can be created but not how it can be destroyed. d. the first law describes how thermal energy can be destroyed but not how it can be created.

Which pair of quantities includes one quantity that increases as the other decreases during simple harmonic motion?

How many astronauts have walked on the moon?