Name: 1. A car moves m/s north at a constant velocity. What is the car's displacement after 2.0 hours?

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1 Name: Applied Physics I Fall 2007 Multiple Choice ( 6 Points ): 1. A car moves m/s north at a constant velocity. What is the car's displacement after 2.0 hours? a.) 40 miles north b.) 120 miles north c.) m north d.) miles south 2. A car is moving at 26 m/s at a constant rate when the driver of the car sees a child run into the street. He slams on the brakes and accelerates at a constant rate of -2.0 m/s 2. How far does the car travel from the point where the driver slams on his brakes until the car comes to a complete stop? a.) 6.5 m b.) 76.6 m c.) 169 m d.) 84.5 m Dy =? 50 meters 3. A boy stands on the edge of a roof of a tall building throws a ball straight up with a velocity of 2.0 m/s. The initial height of the ball is 50 meters. How high does the ball travel above the building? (Note: The path of the ball was straight up and straight down, the path in the diagram was exaggerated so you could see the path.) a.) 0.20 m b.) 0.40 m c.) 20.4 m d.) 0.80 m

2 4. How long was the ball in problem 3 in the air? a.) 3.00 s b.) 3.41 s c.) 6.81 s d.) 5.83 s 50 m Not drawn to scale. Dx =? 5. A boy shoots a golf ball horizontally off a 50 meter tall building. The initial x component of the velocity is 10.0 m/s and the initial y component of the velocity is zero. The forces in the x direction are negligible. The only force that is not negligible in the y direction is the force of gravity. How far from the building does the golf ball land? a.) 31.9 m b.) 204 m c.) 102 m d.) 500 m 6. A student is speeding down Kelly Drive at a constant 90 mph when he passes a policeman at a speed stop. The instant the student passes the policeman, the policeman begins to accelerate from rest at 4 m/s 2. How far does the policeman travel before he catches up to the speeding student? a.) m b.) m c.) m d.) m

3 7. A hiker walks 150 m i 60m j 3m k and stops for a rest. He then walks 40 m i 120m j 2m k. What is the magnitude of the hiker's total displacement? a.) m b.) m c.) m d.) m v = 100 m/s 100 m 8. A rescue plane, flying horizontally at a constant 100 m/s 100 m above the ground, drops a survival package to a stranded hiker. What is the initial velocity of the package? a.) 100 m/s i b.) 0m/ s c.) 100m /s j d.) 100m/ s j Dx =? 9. What is the horizontal distance from the point at which the package in problem 8 was dropped from the plane to the point it hits the ground? (Neglect all forces except for gravitational force.) a.) m b.) 452 m c.) 0.0 m d.) m

4 10. A Septa train starts from rest and accelerates at 1.0 m/s 2. What is the train's speed after 10.0 s? a.) 20.0 m/s b.) m/s c.) m/s d.) 10.0 m/s

5 Problem One ( 20 points ): v= 20 m/s Q = 30 O A golfer hits a golf ball with an initial velocity of 20 m/s at an angle of 30 degrees. The golf ball starts from the ground and lands back on the ground some time later. The golf ball comes to rest in the rough and does not bounce or roll after hitting the ground. a.) (2 pts) What is the initial velocity in the x direction? b.) (2 pts) What is the initial velocity in the y direction? c.) (3 pts) What is the maximum height the ball reaches? d.) (2 pts) What is the y component of the velocity of the ball at the point of the maximum height? e.) (2 pts) What is the x component of the velocity of the ball at the point of the maximum height? f.) (3 pts) What is the total time the ball spent in the air? g.) (3 pts) How far in the x direction does the ball travel before coming to rest on the ground? h.) (3 pts) What is the magnitude of the velocity of the golf ball the instant it hits the ground?

6 Problem Two ( 20 points ): 3.05 m 10.0 m 2.0 m A two meter tall basketball player is standing on the floor 10 m from the basket. He shoots the ball at an angle of 40 degrees with a speed of 10.5 m/s. the basket is 3.05 m high. a.) (4 pts) What is the initial velocity in the x direction? b.) (4 pts) What is the initial velocity in the y direction? c.) (2 pts) What is the maximum height the ball reaches? d.) (4 pts) What is the x component of the velocity of the ball at the point of the maximum height? e.) (4 pts) What is the height of the ball when it reaches the basket? f.) (2 pts) Does he make the basket ( i.e., Is the ball at the right height at the hoop)?

7 Extra Credit ( 5 points ): A hunter sees a monkey hanging from a limb of a tree 20 meters away. The monkey is 40 meters up. The hunter shoots his rifle just as the monkey lets go and drops from rest. Assuming that the hunter was aiming his rifle directly at the monkey, prove the bullet hits the monkey. If the initial speed of the bullet is 50 m/s, at what height does the bullet hit the monkey?