Two boys are throwing a baseball bat back and forth. The ball is 4ft above the ground when it leaves one child's hand with an upward velocity of 36ft/s. If acceleration due to gravity is - 16ft/s^2, how high above the ground is the ball 2 s after it is thrown?

A) 12ft

B) 20ft

C) 76ft

D) 116ft

That's a typo ... if the acceleration of gravity is - 16ft/s^2? Maybe basketball on Mars : P

Free fall equation result from integration of the acceleration equation with respect to time ...

a=g

v=gt+v0

h=gt^2/2+v0t+h0 where v0 and h0 are initial velocity and height respectively ...

Since acceleration, g, is about - 32ft/s^2 not - 16ft/s^2 you get:

h=-16t^2+36t+4 for your height equation.

h (2) = 12 ft