If an arrow is shot upward on the moon with velocity of 21 m/s, its height (in meters) after t seconds is given by h(t)=21t−0.83t^2

Question

a) Find the velocity after 10 seconds

B) Find the velocity after (a) seconds

C) When will the arrow hit the moon

Answer 1

h(t) = 21t - .83t^2 = t(21 -.83t)

velocity = v(t) = h'(t) = 21 -1.66t

after 10 seconds

v(10) = 21-16.6 = 4.4 meters high

after a seconds

v(a) = 21-1.66a meters high

it hits the moon

when

h(t) = 0 = 21t -.83t^2 = t(21-.83t)

21-.83t=0

t = 21/.83 = about 25.3 seconds