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During an experiment, a ball is dropped from a height of 205 feet. The formula h = -16t2 + h subscript 0 can be used to approximate the number of seconds t it takes for the ball to reach height h from an initial height of h subscript 0 in feet. Find the time it takes the ball to reach the ground.

User Fabrizotus
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1 Answer

6 votes

Answer:

4 seconds

Explanation:


h = -16t^2 + h_0

where h=height reached after t seconds


h_0 = Initial Height of the ball

The ball is dropped from a height of 205 feet,


h_0 = 205 feet

We want to determine the time it takes the ball to reach the ground.

i.e. when height of the ball, h=0

Substituting
h_0 = 205 feet and h=0 into the formula


h = -16t^2 + h_0


0 = -16t^2 + 205

Add
16t^2 to both sides


0+16t^2 = -16t^2+16t^2 + 205\\16t^2=205

Divide both sides by 16


(16t^2)/(16)= (205)/(16)\\t^2=12.8125


t=√(12.8125) =3.58 ≈ 4 Seconds

It takes approximately 4 seconds for the ball to reach the ground.

User Paolo Lorenzini
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