Viewing Saved Work Revert to Last Response Submit Answer 4. [-/5 Points] DETAILS LARAPCALC10 2.3.017. The height s (in feet) at time t (in seconds) of a silver dollar dropped from the top of a building is given by s = -16t2 + 525. (a) Find the average velocity on the interval [4, 5] ft/s (b) Find the instantaneous velocities when t = 4 and when t = 5. s'(4) = ft/s s'(5) = ft/s (c) How long will it take the dollar to hit the ground? (Round your answer to two decimal places.) (d) Find the velocity of the dollar when it hits the ground. ( Round your answer to one decimal place.) ft/s hp