A rock, dropped from rest near the surface of an atmosphere-free planet, attains a speed of 20.0 m/s after falling 8.0 meters.
-How long did it take the object to fall the 8.0 meters mentioned?
A)0.40 s
B)0.80 s
C)1.3 s
D)2.5 s
E)16 s

Question

Quizplus · Accepted Answer

The time taken to fall a distance h is given by the formula t = sqrt(2h/g), where g is the acceleration due to gravity. Substituting the values given, we get t = sqrt(2*8/9.81) = 0.80 s. Therefore, the answer is B.

A Rock, Dropped from Rest near the Surface of an Atmosphere-Free