AP Physics B Problem Set

AP Physics B Problem Set

I.A – ProjectileMotion

1. An object is launched horizontally with an initial velocity vo from height h above the ground. Using the given variables and fundamental constants, write an expression for the time t it takes for the object to reach the ground. b) Write an expression for the horizontal distance d the object travels before it strikes the ground.

1. A person skateboarding along a horizontal surface with a constant speed of 1.30 m/s releases a ball from a height of 1.25 m above the ground. a) Find the time it takes for the ball to reach the ground. (Ans. 0.505 s) b) Find horizontal distance the ball travels before it strikes the ground. (Ans. 0.657 m) c) What is the velocity of the ball as it strikes the ground? Describe the angle the ball strikes the ground with the horizontal. (Ans. 5.12 m/s at 75.3° below the horizontal)

1. A mountain climber encounters a crevasse in an ice field. The opposite side of the crevasse is 2.75 m lower, and is separated horizontally by a distance of 4.10 m. To cross the crevasse, the climber gets a running start and jumps in the horizontal direction. a) What is the minimum speed needed by the climber to safely cross the crevasse? (Ans. 5.47 m/s) b) What is the climber’s speed on landing? (Ans. 9.05 m/s)

1. A golfer chips a ball with an initial velocity of 13.5 m/s at 54.0° above the horizontal. The ball lands at the same level from which it was struck. a) What are the horizontal and vertical components of the ball’s initial velocity? (Ans. 7.94 m/s, 10.9 m/s) b) What is the time the ball is in the air? (Ans. 2.22 s) c) What is the horizontal distance the ball travels? (Ans. 17.6 m) d) What is the maximum height reached by the ball? (Ans. 6.06 m)

1. Suppose the golfer in Problem 4 must hit the ball so that it clears a 3.00 m high tree that is horizontal distance of 14.0 m from the point at which the ball is hit. By how much will the ball clear the tree? (Ans. 1.01 m)

1. The archerfish hunts by dislodging an unsuspecting insect from its resting place with a stream of water expelled from the fish’s mouth. Suppose the archerfish squirts water with an initial speed of 2.30 m/s at an angle of 19.5° above the horizontal. When the stream of water reaches a beetle on a leaf at height h above the water’s surface, it is moving horizontally. a) What is the height of the beetle above the surface of the water? ( Ans. 0.0301 m) b) How long does it take for the water to hit the beetle? (Ans. 0.0783 s) b) c) What is the horizontal distance between the fish and the beetle when the water is launched? (Ans. 0.170 m)