Question

1.If an arrow is shot upward on the moon with a velocity of 50 m/s its height (in meters) after t seconds is given by H = 50t - 0.66t2. With what velocity will the arrow hit the moon?
a. -49.5
b. -47
c. -50.1
d. -50
e. -51
2.If an arrow is shot upward on the moon with a velocity of 53 m/s its height (in meters) after t seconds is given by H = 53t - 0.62t2. When will the arrow hit the moon? Round the result to the nearest thousandth if necessary.
a. 85.484
b. 85.473
c. 85.489
d. 85.374
e. 85.485

Answer 1

clearly, due to conservation of energy, etc., the arrow will strike with the same velocity as it left, but in the opposite direction.

just solve 53t - 0.62 t^2 = 0
t(53-0.62t) = 0
t = 53/0.62 = 85.4839