How much oxygen is contained in the atmosphere?
a. 20%
b. 21%
c. 22%
d. 23%
user:
clouds are made up of tiny droplets. what happens to the droplets when they are very heavy?
a. they create another cloud
b. they begin to evaporate
c. they stay in the cloud
d. they fall to earth as rain, precipitation

John throws .4 kg ball with velocity of 18 m/s. hits .2 kg bottle and bottle flies 25 m/s. how fast is ball traveling after hitting the bottle?

Kate is working on a project in her tech education class. she plans to assemble a fan motor. which form of energy does the motor convert most of its electric energy into? a. light energy b. motion energy c. sound energy d. thermal energy

Ablue car pulls away from a red stop-light just after it has turned green with a constant acceleration of 0.5 m/s 2 . a green car arrives at the position of the stop-light 6.5 s after the light had turned green. if t = 0 when the light turns green, at what time does the green car catch the blue car if the green car maintains the slowest constant speed necessary to catch up to the blue car? answer in units of s.