Superman is standing 393m horizontally away from Lois Lane. A villian drops a rock 4 m directly above Lois. I f Superman is to intervene and ctath the brock

acceleration = (change in speed) / (time for the change)

change in speed = (20-120)= -100 m/s.

1.5 min = 90 sec

acceleration = -100/90 = -1.11 m/s^2.

we don't care about the 150kg or the 2,500 meters. they don't make any difference.

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what is the speed of a softball that travels 20m in 2secs

speed = 20/2 = 10 m/s