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Name: ________________________ Class: C Period Date: May 4, 2006 ID: APlanetary Motion - Physics 12Multiple ChoiceIdentify the letter of the choice that best completes the statement or answers the question.____ 1.If a race car travels around corner #3 of the racetrack at twice the speed used on corner #2, the frictional forcerequired to keep the car on the track must be:a. the same.b. twice as great.c. three times as great.d. four times as great.____ 2. An airplane makes a circular turn in its approach to the runway for landing. The air applies a centripetal forceon the wings of the plane that allows it to turn. If the mass of the plane were doubled, the centripetal forcerequired to turn the plane would be:a. the same.b. half as much.c. twice as much.d. four times as much.____ 3.____The loop in a loop-the-loop in a rollercoaster has a radius of curvature of 21 meters.The rollercoaster carloaded with passengers has a mass of 2,200 kilograms. A minimum speed must be maintained so the car stayson the track while it is upside down. The minimum speed is about:a. 14 m/sec.b. 0.31 m/sec.c. 210 m/sec.d. 225 m/sec.4. The mass of an object at the surface of the Earth compared to the mass of the same object at a distance of twoEarth radii from the surface of the Earth is:a. the same.b. one half.c. one quarter.d. one ninth.4 of 4

Name: ________________________ID: A____ 5.________________The graph which best represents the gravitational force between two masses as the distance between themasses changes is:a. Ab. Bc. Cd. D6. If the distance between two objects were doubled, the force of gravitational attraction between the objectswould be:a. the same.b. double the original force.c. one half of the original force.d. one quarter of the original force.7. The force of gravitational attraction between two objects is 20. newtons. If the mass of each object weredoubled, the gravitational force between the objects would be:a. 5.0 newtons.b. 10. newtons.c. 20. newtons.d. 80. newtons.8. A satellite of mass m is orbiting the Earth at a distance r. It experiences a centripetal force F c . Which of thefollowing expressions can be used to calculate its speed?a.F crF cmc.mrF cb.rd. F cmr9. As a car travels around a horizontal circular track at a constant speed, it must undergo a change in which ofthe following quantities?a. mass c. velocityb. speed d. weight2 of 3

Name: ________________________ID: A____ 10. Kepler's first law of planetary motion says that the planets followa. circular paths around the sun c. hyperbolic paths around the sunb. elliptical paths around the sun d. parabolic paths around the sun____ 11. A physics student observes glancing two-dimensional collisions between identical billiard balls. Which of thefollowing observations confirms that the collision between a moving (incident) ball and a stationary (target)ball is elastic?a. The incident ball bounces back.b. The target ball has a much higher velocity after impact.c. The two balls have identical speeds after impact.d. The two balls travel along paths separated by 90 o angle after impact.____ 12. In the two-dimensional collision experiment that was performed in class (where an incident ball was launchedfrom the projectile launcher and experienced a glancing collision with a stationary target ball in front of thelauncher), pretend that we used a steel incident ball and a glass target ball, which is half the mass of the steelball. Which of the following statements best describes how the displacement vectors of the two balls could bedrawn to represent momentum vectors?a. They may be used as they are.b. The displacement of the glass ball must be cut in half.c. The displacement of the glass ball must be doubled.d. The displacement of the steel ball must be cut in half.Short Answer13. Where do countries usually try to locate their rocket launch sites on the Earth? Why? [2]14. Suppose that the Sun's mass was four times the actual value, and that the Earth's radius of orbit wasunchanged. Would a year be longer or shorter? By what factor would the period change? [3]Problem15. A 23.0 kg child sitting on a merry-go-round makes 3.00 revolutions in 30.0 s. The child is 2.75 m away fromthe centre of the merry-go-round. What coefficient of friction is necessary to keep the child from sliding offof the merry-go-round and ruining his trip to the amusement park? [6]16. Spiderman has a mass of 80.0 kg. He swings in a circular arc on a web that is 4.00 m long.a) Draw a free body diagram of the forces acting on Spiderman at the bottom of the swing. [1]b) If his speed is 3.20 m/s at the bottom of the swing, what is the tension in the web? [3]c) If the maximum tension the web can withstand is 1800 N, what is the minimum speed Spiderman wouldhave to have at the bottom in order to break the web? What direction would he go immediately after the webbroke? [4]17. A satellite is orbiting the earth at a height of 2000 km. How many hours would it take this satellite to makeone orbit? [5]18. An asteroid has an average orbital radius of 5.8 × 10 11 m. What will be its orbital period around the Sun? [4]3 of 3

ID: APlanetary Motion - Physics 12Answer SectionMULTIPLE CHOICE1. ANS: D DIF: intermediate2. ANS: C DIF: intermediate3. ANS: A DIF: advanced4. ANS: A DIF: basic5. ANS: A DIF: basic6. ANS: D DIF: intermediate7. ANS: D DIF: intermediate8. ANS: A9. ANS: C10. ANS: B11. ANS: D12. ANS: BSHORT ANSWER13. ANS:Countries usually try to locate their launch sites nearthe equator because this is the part of the earth that ismoving the fastest and will give the rockets the greatest initial velocity.14. ANS:GMSince v = for the Earth (treating it as a satellite around the Sun), a sun with a mass 4 times largerr 2would double the speed of the Earth.Since T = 2πr, this would mean the period of the Earth is cut in half, so the year would be half as long.v1 of 4

ID: APROBLEM15. ANS:T = 30.0s3.00revT = 10.0sv = 2πrTv = 2π(2.75)10.0v = 1.73m / sF c= ma cF f= m v 2rµF N= m v 2rµm/ g = m/ v 2rµ = v 2grµ = (1.73) 2(9.8)(2.75)µ = 0.112 of 4