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36 votes
36 votes
an object is launched at 4 ft./s from 88 foot tall platform the objects height H in feet after T seconds is given by the equation H=-16T^2+8t+80 when does the object strike the ground

User Praveen Srinivasan
by
2.7k points

1 Answer

6 votes
6 votes

Answer:

1.5seconds

Explanation:

When the ball hits the ground, the height is equal to zero. So find t when H=0:

H=16t²+8t+80

0=16t²+8t+80

0=2t²+t+10

0=(2t-3)(t+2)

So (2t-3)=0, or (t+2)=0

So t=1.5 or t=-2. Time can't be negative though, so we take our answer as 1.5seconds

User JaredL
by
2.8k points
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