Question

An object is launched from an initial height of 5 feet and initial upward velocity of 65 feet per second. Which of the following could be used to determine at what times the object's height is less than 50 feet? [Let t represent time.]

Answer 1

what is the equation that your using?

Answer 2

Answer choices:

\[ -16t^2 + 65t + 5 < 50\] \[-16t^2 + 65t + 5 > 50\] \[-16t^2 + 5t + 65 > 50\] \[-16t^2 + 5t + 65 < 50\]

Answer 3

in feet/s

height = -16t^2 + (initial velocity)t + initial height

(the -16t^2 comes from the gravitational constant, after units have been converted to SI)

since they want the height less than 50, set the height < 50