General: Impact Velocity If a steel ball is tossed from the top of the Burj Khalifa in D...

General: Impact Velocity If a steel ball is tossed from the top of the Burj Khalifa in Dubai, the tallest building in the world, its height above the ground t seconds later will be s(t) = 2717 - 16t² feet (neglecting air resistance).

a. How long will it take to reach the ground? [Hint: Find when the height equals zero.]

b. Use your answer to part (a) to find the velocity with which it will strike the ground. (This is called the impact velocity.)

c. Find the acceleration at any time t. (This number is called the acceleration due to gravity.)