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AP Physics U3 More Projectiles Problems Key
1) A ball is thrown up at a 30o angle with an initial velocity of 5 m/s. Calculate the horizontal range?
Xf = VxT + X0
Yf = 1/2 AT2 + VyT + Y0
Vx= 5m/s Cos 30 o= 4.3m/s
Vy= 5m/s sin 30 o= 2.5m/s
X=2.16 m
T=0.5s
2) A water balloon is launched at 32 m/s at some angle. If the balloon takes 5.2 s to land, what angle
was it launched at? How far horizontally did the balloon travel?
Xf = VxT + X0
V= 32m/s
Yf = 1/2 AT2 + VyT + Y0
X=97 m
Vy=26.0m/s
Vx= 18.8 m/s
Vy= 26.0m/s
3) If a ball is launched from a 15m cliff at a 35o angle with an initial velocity of 8 m/s, how far from the
cliff does the ball land?
V = 8m/s
Xf = VxT + X0
Yf = 1/2 AT2 + VyT + Y0
Vx= 6.5 m/s
Vy= 4.5 m/s
X = 14.7m
T=2.24s
4) If a ball is thrown straight down at 17 m/s from a plane with an altitude of 650m moving horizontally
at 78 m/s, how far does the ball travel horizontally?
Xf = VxT + X0
Yf = 1/2 AT2 + VyT + Y0
X = 764m
T=9.8s
5) If a ball is fired horizontally from a 30 m cliff at 15m/s, how far from the cliff will it land?
X = 37m
T=2.45s
6) How fast must a ball be fired horizontally from a 30m cliff to land 50m away?
Vx= 18.8 m/s
T=2.45s
7) A ball is fired from a 30m cliff at 14.5m/s and lands 40m away after 3.5sec. From what angle was the
ball launched?
Xf = VxT + X0
Yf = 1/2 AT2 + VyT + Y0
Vx = 11.4 m/s
θ= 380
Vy= 8.9 m/s
4*) If a ball is fired from a cannon at a 450 angle from a 20m cliff and just lands on a 30m cliff 15m away,
how fast did it leave the cannon?
450 so Vx = Vy
Xf = VxT + X0
T=15/Vx
Yf = 1/2 AT2 + VyT + Y0
30 = -5(
T=15/Vx
V = 21.2m/s
Vx = 15m/s
)2 + Vx (
T=15/Vx
) + 20