Question

A mannequin is dropped from the top of a fire department training tower onto a rescue trampoline 67 feet below. How long does it take before the mannequin is caught by the trampoline? Use h(t) = -16t2 + 67.

Answer 1

I got 2.09375 seconds using differential calc, but -2.046 using the quadratic formula

Explanation:

Im unsure which technique is supposed to be used her. I didnt know if this was a calculus problem or a quadratic equation. So, choose from the two answers depending on which class this is for

Differential:

h(t) is the height with respect to time. So I changed it to h'(t) and took the derivative of the function using the power rule.

Quadratic:

There is no B here so the formula boils down to the square root of -4ac/2a