physics

posted by .

Marie shoots an arrow vertically upward at a sandhill crane. If the arrow travels to a maximum height of 99.5 meters, calculate how fast it was shot.
And, for how much time was Marie's arrow in the air?

• physics -

v = Vi - 9.8 t
0 = Vi - 9.8 t
Vi = 9.8 t

99.5 = Vi t -4.9 t^2
99.5 = 9.8 t^2 - 4.9 t^2 = 4.9 t^2
t = 4.5 seconds to top
so
Vi = 9.8 * 4.5 = 44.2 m/s

You could also do this by conservation of energy
(1/2) m Vi^2 = m g h
so
Vi = sqrt (2*9.8*99.5)
= 44.2 m/s

Similar Questions

1. Physics

Three arrows are shot at different angles. A red arrow is shot at 30degrees, a blue arrow is shot at 45degrees, and a yellow arrow is shot at 60degrees. A) Which arrow goes the farthest?
2. Physics 11

Mark Ji shoots a 40gram arrow straight up in the air at 30m/s during a home archery training session a. assuming no air resistance, what is the maximum height that the arrow could reach?
3. physics

An arrow is short vertically upward with an initial speed of 25m/s. When it's exactly halfway to the top of its flight, a second arrow is launched vertically upward from the same spot. The second arrow reaches the first arrow just …
4. physics

An archer shoots an arrow horizontally with an initial velocity of 100 meters per second from a building that is 20 meters high. (air resistance is neglected) a. Calculate the time when the arrow is in the air. b. Find the horizontal …
5. physics

Marie shoots an arrow vertically upward at a sandhill crane (she misses the crane, so you PETA members can relax). If the arrow travels to a maximum height of 99.5 meters, calculate how fast it was shot. And, for how much time was …
6. physics

Marie shoots an arrow vertically upward at a sandhill crane. If the arrow travels to a maximum height of 99.5 meters, calculate how fast it was shot. And, for how much time was Marie's arrow in the air?
7. Physics (Mechanics)

Marie shoots an arrow vertically upward at a sandhill crane. If the arrow travels to a maximum height of 99.5 meters, calculate how fast it was shot. And, for how much time was Marie's arrow in the air?
8. physics

an arrow is shot vertically upward after 2s it is at a height of 36m although this is not necessarily the highest point with what velocity was the arrow shot what is the maximum height reached by the arrow how long is the arrow in …
9. physics

an arrow is shot vertically upward 2 seconds later it is at a height of 42m with what velocity was the arrow shot, how long is the arrow in flight altogether
10. physics

an arrow is shot vertically upward 2 seconds later it is at an height of 42m (not necessarily the highest point) with what velocity was the arrow shot how long was the arrow in flight altogether

More Similar Questions