PHYSICS: a ball is thrown upward in the air, and its height above the ground after t seconds is:

Question

H(t) = 64t - 16t^2 ft

find the time t when the ball will be traveling downward at 16ft per second

Answer 1

Is your physics course a calculus based course?

If so, since they gave us the function of height, the derivative of the height function would give us velocity.

v(t) = H'(t) = 64 – 32t

Since they are asking for when the ball is traveling downward at 16 ft/s, the velocity will be equal to –16 ft/s since velocity is negative in the downward direction.

plug in –16 for v(t) and solve for t.

–16 = 64 – 32t–

–48 = –32t

t = 1.5 s FINAL ANSWER