Question

The height above the ground (in feet) of a ball dropped from the top of a 30-foot-tall building after t seconds is given by the polynomial −16t2+30. what is the height of the ball after 12 second? write your answer without units.

Answer 1

If h(t)=-16t²+30, then the ball hits the ground, or h(t)=0, at:
0=-16t²+30
16t²=30
t²=1.875
t=1.37 seconds
The ball is on the ground after 1.37 seconds, so, after 12 seconds the height of the ball is 0
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