+0  
 
0
122
1
avatar

A ball is thrown from the top of a building. The height, h-meters above ground, can be moddled by h = 12 - 5t - 2t^2. where t is the time after it leaves the ground

 

A. What is the height of the ball before it touches the ground?

 

B.At what time will the ball strike the ground again?

 Aug 19, 2018
 #1
avatar
+2

A  I assume this question means: " what is the initial height of the ball?"    Let t= 0

Then h = 12  - 5(0)- 2(0)^2 = 12 meters

 

B. This occurs when h= 0 

  0 = 12 - 5t - 2 t^2         

0 = 2t^2 +5t - 12

  Use Quadratic Formula to find    t = 1 1/2 sec

 Aug 19, 2018

4 Online Users

avatar