Question

A toy rocket is launched straight up into the air with an initial velocity of 60 ft/s from a table 3 ft above the ground. If acceleration due to gravity is –16 ft/s2, approximately how many seconds after the launch will the toy rocket reach the ground? h(t) = at2 + vt + h0 0.05 s 2.03 s 3.80 s 3.70 s

Answer 1

The equation is:
h ( t ) = - 16 t² + 60 t + 3
The toy rocket will reach the ground when: h ( t ) = 0
- 16 t² + 60 t + 3 = 0
$t _{12} = \frac{-60+/- \sqrt{3600+192} }{-32}$
t 1 = - 0.05
t 2 = 3.8
Answer:
C ) 3.80 s