1. Projectile Motion And Centripetal acceleration
Chapter 6 Review
Projectile Motion
And
Centripetal acceleration

2. Topics Tested on the Exam
Projectile Motion
Centripetal Acceleration
Problems
Concepts
Problems
Concepts 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

3. Projectile 1
A golfer is teeing off on a m long, level, par 3 hole. The ball leaves with a velocity of 40.0 m/s at 50.0o to the horizontal. Assuming that she hits the ball on a direct path to the hole, how far from the hole will the ball land? (no bounces or rolls)
Distance from the hole ≈ 9.2 m
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4. Projectile 2
A canon ball fired horizontally from a cliff has a velocity directed at 60o below horizontal when it hits the ground 3.0 seconds later. How high was the cliff?
Cliff height ≈ 14.7 m
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5. Projectile 3
A flare gun launches a bright, glowing flare at 60 m/s at an 80° angle above horizontal. How high does it go?
Max height ≈ 178 m
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6. Projectile 4
A human cannonball is shot from a cannon at 25 m/s at an angle of 22°. If he leaves the cannon at ground level and lands in a net also at ground level, how far does the person travel along the horizontal
Range ≈ 44.3 m
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7. Projectile 5
A lacrosse player throws the ball down field to a teammate. The ball leaves her stick 1.2 meters above the ground, with a velocity of 13 m/s at an angle of 38 degrees to the horizontal. The ball is caught 12.5 meters down the field. What is the height of the ball when it is caught?
Height of catch ≈ 3.67 m
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8. Projectile 6
A rock is thrown up off a cliff. Where is the vertical velocity zero?
The vertical velocity is zero as the rock reaches its maximum height.
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9. Projectile 7
A paper rocket is launched vertically from the ground and then lands on the ground. Compare the speed of the rocket at the end of the trip and the beginning of the trip (ie, is one bigger, smaller, equal?)
The beginning and ending speeds will be the same. (yet opposite in direction)
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10. Projectile 8
A rock is thrown from a window. Compare the speed of the rock horizontally at the end (just before it hits the ground) and the beginning of the trip (ie, is one bigger, smaller, equal?)
The horizontal speeds at the beginning and the end will be equal. Since horizontal acceleration is zero the velocity will remain constant.
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11. Projectile 9
True or False. A hunter in a tree stand is at the same height as a squirrel. The hunter fires a bullet at a positive angle in order to hit the squirrel. The maximum height is achieved half way through the bullets trajectory.
True. (only because the bullet starts and ends at the same height)
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12. Centripetal 10
A CD spins with a frequency of 1800 revolutions per minute, what is the period of the spin of the compact disc?
Period = 1/30 sec ≈ sec
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13. Centripetal 11
You can spin a pizza dough overhead with a frequency of 60 revolutions per minute. Find the linear speed of a pepperoni 10 cm from the center of the pizza.
Velocity ≈ 0.63 m/sec
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14. Centripetal 12
The earth turns on its axis approximately once every 24 hours. The radius of the earth is meters. If something brought the earth to a screeching halt, how fast would people on the equator fly off the earth.
The velocity of a person standing on the equator is ≈ 464 m/sec.
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15. Centripetal 13
A kg mass is attached to a string 75 cm long and swings in a horizontal circle, revolving once every 0.80 s. What is the centripetal acceleration of the mass.
Acceleration ≈ m/sec2
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16. Centripetal 14
Will the centripetal force and the centripetal acceleration work in the same direction or different directions? What equation shows the relationship between the two?
Always the same direction as one another. F = m a
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17. Centripetal 15
What provides the force required to keep a curving vehicle on the road?
The friction between the road and the tires.
(static friction or kinetic friction?)
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18. Centripetal 16
What provides the force required to keep a bucket full of water from spilling as it swings upside down?
The pulling on the handle from the person swinging the bucket.
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19. Centripetal 17
What acceleration is required to keep the water in a bucket as it swings upside down?
Any centripetal acceleration greater than the acceleration of gravity.
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