1) A fireman, 30 m away from a burning building, directs a streamjet of water fr

Question

1) A fireman, 30 m away from a burning building, directs a streamjet of water from a
ground level fire hose at an angle of 35.7 degrees above thehorizontal. The acceleration of gravity is 9.8 m/s2 . If the speedof the stream as it leaves the hose is 38.6 m/s, at what heightwill the stream of water strike the building? Answer in units ofm.

2) The initial speed of a cannonball is 600 m/s. The accelerationof gravity is 9.8 m/s2 . The cannon and target are at the sameelevation. If the ball is to strike a target that is at ahorizontal distance of 3.6 km from the cannon, what is the minimumtime of flight for the ball? Answer in units of s.

Thank you for your help!

Explanation / Answer

to clarify, calculate the time is takes the cannon ball toshoot straight up (x2 for falling down)
Your initial velocity (vi) is 600 m/s
Your final velocity (vf) is 0 (remember at the peak of an arc thevelocity is zero) Your acceleration is -9.8m/s^2
Solve for t

Vf = Vi + a(t)

0 = 600 + -9.8(t) -600/-9.8 = t
t = 61.22

Multiply the time by 2 to get the total time spent in the air forthe cannon ball

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