Answer:
138.18 minutes
Explanation:
= Latent heat of water at 0°C = 80 cal/g
m = Mass of water = 570 g
Heat removed for freezing
Let N be the number of cycles and each cycle removes 56 cal from the freezer.
So,
Each cycle takes 10 seconds so the total time would be
The total time taken to freeze 138.18 minutes
The ball took half of the total time ... 4 seconds ... to reach its highest
point, where it began to fall back down to the point of release.
At its highest point, its velocity changed from upward to downward.
At that instant, its velocity was zero.
The acceleration of gravity is 9.8 m/s². That means that an object that's
acted on only by gravity gains 9.8 m/s of downward speed every second.
-- If the object is falling downward, it moves 9.8 m/s faster every second.
-- If the object is tossed upward, it moves 9.8 m/s slower every second.
The ball took 4 seconds to lose all of its upward speed. So it must have
been thrown upward at (4 x 9.8 m/s) = 39.2 m/s .
(That's about 87.7 mph straight up. Somebody had an amazing pitching arm.)
