Problem 72A

Velocity If a rock is dropped from a 144-ft building, its position (in feet above the ground) is given by s(t) = −16t2 + 144, where t is the time in seconds since it was dropped.

a. What is its velocity 1 second after being dropped? 2 seconds after being dropped?

b. When will it hit the ground?

c. What is its velocity upon impact?

Solution:

Step 1 of 2:

In this problem, we need to find the velocity 1 second after being dropped and 2 seconds after being dropped.