Projectile Motion: Practice Problems & Solutions

1. An object is projected horizontally at 8.0 m/s from the top of a 122.5 m cliff. How far from the base of the cliff will the object strike the ground?

2. An arrow is shot at 30.0° angle with the horizontal. It has a velocity of 49 m/s.

a) How high will it go?

b) What horizontal distance will the arrow travel?

3. A person kicks a rock off a cliff horizontally with a speed of 20 m/s. It takes 7.0 seconds to hit the ground, find:

a) height of the cliff

b) final vertical velocity

c) range

4. A ship fires its guns with a speed of 400 m/s at an angle of 35° with the horizontal. Find the range and maximum altitude.

5. A basketball is held over head at a height of 2.4 m. The ball is lobbed to a teammate at 8 m/s at an angle of 40°. If the ball is caught at the same height it was tossed at, how far away is the teammate?

6. Suppose the ball in #6 was missed, what would the range be?

7. An athlete executing a long jump leaves the ground at angle of 30.0° and travels 7.80 m.

a) What is the takeoff speed?

b) If the takeoff speed was increased by 5.0%, how much longer would the jump be?

8. A hunter aims directly at a target (on the same level) 140 m away. If the bullet leaves the gun at a speed of 280 m/s, by how much will the bullet miss the target?

9. A ball is thrown horizontally from the roof of a building 50 m tall and lands 45 m from the base. What was the ball’s initial speed?

10. A fire hose held near the ground shoots water at a speed of 7.5 m/s. At what angle should the nozzle point in order that the water land 2.0 m away? Why are there two different answers to this problem?

11. A bullet traveling 800 m/s horizontally hits a target 180 m away. How far does the bullet fall before it hits the target?

12. A student threw a ball horizontally out of a window 8.0 m above the ground. It was caught by another student who was 10.0 m away. What was the initial velocity of the ball?

13. A baseball was hit at 45 m/s at an angle of 45° above the horizontal.

a) How long did it remain in the air?

b) How far did it travel horizontally?

14. A camper dives from the edge of a swimming pool at water level with a speed of 8.0 m/s at an angle of 30.0° above the horizontal.

a) How long is the diver in the air?

b) How high does the diver go?

c) How far out in the pool does the diver land?

Answers:

1) 40 m

2) a) 32 m

b) 2.2 x 102 m

3) a) 2.4 x102 m

b) 69 m/s

c) 1.4 x 102 m

4) a) 2.7 x 103 m

b) 1.5 x104 m

5) 6.2 m

6) 8.4 m

7) a) 9.4 m/s

b) 0.90 m

8) 1.23 m

9) 14 m/s

10) 10°

11) 0.26 m

12) 7.7 m/s, –>

13) a) 6.6 s

b) 2.1 x 102 m

14) a) 0.82 s

b) 0.82 m

c) 5.7 m