i. a
ii. b
iii. c3.11 Randy Johnson throws a baseball horizontally from the top of a building as fast as his 2004 record of 102.0 mph (45.6 m/s).
How much time passes until it moves at an angle 13.0 degrees below the horizontal? Ignore air resistance.
s
3.12 Sam tosses a ball horizontally off a footbridge at 3.1 m/s. How much time passes after he releases it until its speed doubles?
s3.13 You are in a water fight, and your tricky opponent, wishing to stay dry, goes into a nearby building to spray you from above.
His first attempt falls one-third of the way from the base of the building to your position. He climbs up to a higher window and
shoots again, and manages to give you a good soaking. In both cases, he aims his water gun parallel to the ground. What is
the ratio of his first height to his second height?
i. 1 to 1
ii. 1 to 2
iii. 1 to 3
iv. 1 to 4
v. 1 to 9
vi. 1 to 11
3.14 You fire a squirt gun horizontally from an open window in a multistory building and make note of where the spray hits the
ground. Then you walk up to a window 5.0 m higher and fire the squirt gun again, discovering that the water goes 1.5 times as
far. Ignore air resistance. How long does the second shot take to hit the ground?
s
Section 5 - Interactive problem: the monkey and the professor
5.1 Using the simulation in the interactive problem in this section, where should the monkey aim the bazooka? Why?
i. Above the professor's glove
ii. At the professor's glove
iii. Below the professor's gloveSection 7 - Projectile motion: juggling
7.1 A juggler throws a ball from height of 0.950 m with a vertical velocity of + 4.25 m/s and misses it on the way down. What is its
velocity when it hits the ground?
m/s7.2 You are returning a tennis ball that your five-year-old neighbor has accidentally thrown into your yard, but you need to throw it
over a 3.0 m fence. You want to throw it so that it barely clears the fence. You are standing 0.50 m away from the fence and
throw underhanded, releasing the ball at a height of 1.0 m. State the initial velocity vector you would use to accomplish this.
( , ) m/s7.3 Your friend has climbed a tree to a height of 6.00 m. You throw a ball vertically up to her and it is traveling at 5.00 m/s when it
reaches her. What was the speed of the ball when it left your hand if you released it at a height of 1.10 m?
m/s7.4 Two people perform the same experiment twice, once on Earth and once on another planet. One observes from the top of a
40.5 m cliff, and the other stands at ground level. The person at the bottom throws a ball at a speed of 31.0 m/s at a 75.4°
angle above the horizontal. (a) When this experiment is being conducted on Earth, what vertical velocity would you expect
the ball to have when it reaches a height of 40.5 m? (b) On the other planet, the ball is observed to have a vertical velocity of
24.5 m/s when it reaches that height. Assuming there are no forces besides gravity acting on the ball, what is the acceleration
due to gravity on the other planet? State your answer as a positive value, just as g is stated.
(a) m/s
(b) m/s^27.5 A friend of yours has climbed a tree to a height of 12.0 m, but he forgot his bag lunch and is very hungry. You cannot toss it
straight up to him because there are branches in the way. Instead, you throw the bag from a height of 1.20 m, at a horizontal
distance of 3.50 m from the location of your friend. If you want the bag to have zero vertical velocity when it reaches your
friend, what must the horizontal and vertical velocity components of your throw be? Assume you are throwing the bag in the
positive horizontal direction.
( , ) m/s