The measure of the distance an object travels in a certain length of time is the object's a) direction. b) energy. c) position. d) speed.

D. Speed

Speed is the how far you go in a certain amount of time.

i think the answer is

D

1.solid

2.carbon dioxide

3.helium

8 m/s because for him to get the same amount of energy as ray is putting out, bobby, who weighs half as much as ray, needs to run twice as fast.