At the same moment,one rock is dropped and one is thrown downward with an initial velocity of 10 m/s from the top of a 300 m building.How much earlier does the thrown rock strike the ground? (Disregard air resistance. )
A)0.95 s
B)0.66 s
C)0.85 s
D)They land at exactly the same time.

Question

Quizplus · Accepted Answer

The time taken for the dropped rock is calculated using the equation $ h = \frac{1}{2}gt^2 $, which gives $ t \approx 7.75 $ seconds. For the thrown rock, use $ h = v_i t + \frac{1}{2}gt^2 $, which gives $ t \approx 6.8 $ seconds. The difference is approximately 0.95 seconds.

At the Same Moment,one Rock Is Dropped and One Is