The distance d (in feet) a penny falls from the window of a building is represented by d = 16t^2 where t is the time (in seconds) it takes for a penny to hit the ground. How long does it take for the penny to hit the ground when it falls from a height of 400 feet?

Question

Mathematics

Ruth Price

6 September, 14:40

The distance d (in feet) a penny falls from the window of a building is represented by d = 16t^2 where t is the time (in seconds) it takes for a penny to hit the ground. How long does it take for the penny to hit the ground when it falls from a height of 400 feet?

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Answers (1)

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Erik · Answer 1

5 seconds

Step-by-step explanation:

d = 16t^2

You are given the distance, d, and you need to find the time, t. Replace d with the given distance, 400 ft.

d = 400

400 = 16t^2

Switch sides.

16t^2 = 400

Divide both sides by 16.

t^2 = 25

Take the square root of both sides.

t = 5

Answer: 5 seconds