Clouds dump around 100 billion gallons of water on rainforests each year. how much rain is evaporated from the rivers, lakes and surface of rainforests each year?
a) around 100 billion gallons
b) unable to tell from the information given
c) significantly less than 100 billion gallons
d) significantly more than 100 billion gallons

An athlete swings a ball, connected to the end of a chain, in a horizontal circle. the athlete is able to rotate the ball at the rate of 8.13 rev/s when the length of the chain is 0.600 m. when he increases the length to 0.900 m, he is able to rotate the ball only 6.04 rev/s. (a) which rate of rotation gives the greater speed for the ball? 6.04 rev/s 8.13 rev/s (b) what is the centripetal acceleration of the ball at 8.13 rev/s? m/s2 (c) what is the centripetal acceleration at 6.04 rev/s? m/s2