Question

A rocket's path is modeled by y=-16t2 + 80t.

When will the rocket hit the ground?

Answer 1

t=5

Explanation:

y represents height above the ground.

so when it touches the ground height above the ground =0

y=-16t²+80 t

it will hit the ground when y=0

-16t²+80t=0

-16t(t-5)=0

either t=0 or t-5=0

or t=5

t=0 gives initial value.(rejected)

t=5