If you took a 20 g rock from the Earth to the moon, which would change? a. volume
b. mass
c. weight
d. density

Answer asap! the weather patterns on earth are shown in this image. explain why there are convection currents; why there are hotter and colder parts of earth.

Students design a model roller-coaster track. they place a rubber ball at the highest point on the track and let it go. the ball rolls along the track pulled only by the force of gravity. eventually, it comes to a stop. which change to the design will result in the ball moving the greatest distance?

Cathy is pedaling down a steep hill on her bicycle and wants to be able to coast up the next hill, which is 25 meters high, without pedaling. cathy and her bicycle have a mass of 75 kg. assuming her bicycle is 100% efficient, what would her speed have to be?