Math gurus--need help with Algebra I problem

[EKS]

This problem comes out of the Larson Algebra I text (Common Core edition).

 

Fenway Park is a Major League Baseball park in Boston, Massachusetts. The park offers seats on top of the left field wall. A person sitting in one of these seats accidentally drops his sunglasses on the field. The height h (in feet) of the sunglasses can be modeled by the function h = -16t^2 + 38 where t is the time (in seconds) since the sunglasses were dropped. Find the time it takes for the sunglasses to reach the field. Round your answer to the nearest hundredth of a second.

 

OK--I have the teacher's edition, so I have the answer (1.54 seconds) and I know how they got it (by substituting 0 in for h). I'm assuming that the equation means that the wall is 38 feet high and that h is actually the height *above* the wall. Isn't that different than what they actually say, which is that h is the "height of the sunglasses"?

 

Or am I just being totally dense here?

[Kathy in Richmond]

You're right that 38 is the wall height, but here h is the height of the sunglasses above the field, not above the wall. The values of h that you compute with that equation will always be numbers less that 38, since you're always subtracting the positive amount 16t^2 from 38. They start at h= 38 when t=0, and decrease to h=0 when t=1.54 seconds.

[EKS]

I get it now. Thank you both!

 

It seems to me that the problem could be written more clearly if they would have worded it this way:

 

Fenway Park is a Major League Baseball park in Boston, Massachusetts. The park offers seats on top of the left field wall, which rises 38 feet above the field. A person sitting in one of these seats accidentally drops his sunglasses on the field. The height h (in feet) of the sunglasses as they fall to the ground can be modeled by the function h = -16t^2 + 38 where t is the time (in seconds) since the sunglasses were dropped. Find the time it takes for the sunglasses to reach the field. Round your answer to the nearest hundredth of a second.