Solve the problem.
-A rock falls from a tower that is 117.6 m high. As it is falling, its height is given by the formula h = 117.6 - 4.9t2. How many seconds will it take for the rock to hit the ground (h=0)?
A) 4.9 s
B) 10.6 s
C) 10.8 s
D) 2,800 s

Question

Quizplus · Accepted Answer

To find the time it takes for the rock to hit the ground, set h = 0 and solve for t: 0 = 117.6 - 4.9t^2. Rearranging gives 4.9t^2 = 117.6. Dividing both sides by 4.9 gives t^2 = 24. Solving for t, we find t = sqrt(24), which is approximately 4.9 seconds.

Solve the Problem. -A Rock Falls from a Tower That Is 117.6 M