Which of the following is an example of a lever?
a. knife
b. screw
c. nutcracker
d. pencil sharpener

Moon effect. some people believe that the moon controls their activities. if the moon moves from being directly on the opposite side of earth from you to being directly overhead, by what percentage does (a) the moon's gravitational pull on you increase and (b) your weight (as measured on a scale) decrease? assume that the earth–moon (center-to-center) distance is 3.82 × 10^8 m, earth's radius is 6.37 × 10^6 m, moon's mass is 7.36 × 10^22 kg, and earth's mass is 5.98 × 10^24 kg.

Do you agree with scientist’s prediction about the warming of alaska and other polar regions?

Sound is a disturbance that travels through a medium as a