Problema Solution

A rocket is launced from the top of an 30 foot cliff with an initial velocity of 160 feet per second . The height h, of the rocket after T seconds is given by the equation h= -16T^2+160T+30. How long after the rocket is launced will it be 10 feet from the ground?

T=______ seconds

Answer provided by our tutors

The equation that describes the trip of the rocket is:

h(T) = -16T^2+160T+30

We need to find T such that h(T) = 10 ft. For that we need to solve the quadratic equation and find the positive roots (since the time T can not be negative):

-16T^2+160T+30 = 10

........

click here to see the equation solved for T

........

T = 10.12 sec

In 10.12 seconds the rocket will be 10 feet from the ground.