a rock is thrown from one side of a river to another. the function h(t) = -16t^2 + 80t + 30 gives the height in inches of the rock t second after it has been thrown. find h (2.5) . what does h(2.5) represent in the context of this problem. does it make sense to find h (-10) in the context of this problem

1 answer

To find \( h(2.5) \), we can substitute \( t = 2.5 \) into the function \( h(t) = -16t^2 + 80t + 30 \).

Calculating \( h(2.5) \):

\[ h(2.5) = -16(2.5)^2 + 80(2.5) + 30 \]

First, calculate \( (2.5)^2 \):

\[ (2.5)^2 = 6.25 \]

Now substitute this value into the equation:

\[ h(2.5) = -16(6.25) + 80(2.5) + 30 \]

Calculating each term:

\[ -16(6.25) = -100 \] \[ 80(2.5) = 200 \]

Combining all the terms:

\[ h(2.5) = -100 + 200 + 30 \] \[ h(2.5) = 100 + 30 = 130 \]

Thus, \( h(2.5) = 130 \).

Interpretations:

In the context of this problem, \( h(2.5) = 130 \) means that 2.5 seconds after the rock was thrown, its height above the ground is 130 inches.

About \( h(-10) \):

Now, regarding \( h(-10) \):

Finding \( h(-10) \) would represent the height of the rock at -10 seconds, which does not make sense in this context since time cannot be negative in this scenario. Therefore, it is not meaningful to find \( h(-10) \) as it does not correspond to a real point in time after the rock has been thrown.