Question

Charlize wants to measure the depth of an empty well. She drops a ball from a height of 3 feet into the well

and measures how long it takes the ball to hit the bottom of the well. She uses a stopwatch, starting when
she lets go of the ball and ending when she hears the ball hit the bottom of the well. The polynomial
-16€* + 3 gives the height of the ball after t seconds. Her stopwatch measured a time of 3.1 seconds. How
deep is the well?

Answer 1

about 151 feet

Explanation:

The height of the ball at a time of 3.1 seconds is given by Charlize's equation as ...

h(3.1) = -16(3.1)^2 +3 = -150.76 . . . feet

The well is about 151 feet deep.

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Comment on this measurement

The speed of sound is sufficiently slow that it will make a difference in the time Charlize records. She would get a more accurate measurement if she were able to see the ball hit bottom.