A stone is thrown into the air from a bridge over a river. The stone falls into the river. The height of the stone, h(t) metres, above the river t seconds after the stone was thrown is given by h(t)=-5t^2+10t+7
a) determine the maximum hieght of the stone above the water?
b) how long does it take the stone to reach its maximum height?

Question

A stone is thrown into the air from a bridge over a river. The stone falls into the river. The height of the stone, h(t) metres, above the river t seconds after the stone was thrown is given by h(t)=-5t^2+10t+7
a) determine the maximum hieght of the stone above the water?
b) how long does it take the stone to reach its maximum height?

shelby1290 · Answer

I solved it using a graphing calc and got x=1 and y=12 as my maximum

nuttyliaczar · Answer

If you want to find the maximum you want to set the derivative equal to 0 and solve for t. Then plug that back into the original position function

nuttyliaczar · Answer

Since this is a parabola, you know it only has one solution as its maximum (you can picture only one max point on a hill)

nuttyliaczar · Answer

As for the time it takes to get there, that is the t you just solved for

shelby1290 · Answer

So is my answer (1,12) for both the maximum height and the time it would take for the stone to reach it's maximum height?

koikkara · Answer

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