 PhysicsBowl 2016 Printer Friendly Version
Refer to the following information for the next 25 questions.

Use g = 10 N/kg throughout this contest.

Select the single answer that provides the best response to each question.

Correct answers will be awarded one point; incorrect answers and leaving an answer blank will be awarded zero points. There is no additional penalty for incorrect answers. All questions are equally weighted, but are not necessarily the same level of difficulty.

A hand-held calculator may be used. Its memory must be cleared of data and programs. You may use only the basic functions found on a simple scientific calculator.

1. A car drives anticlockwise (counterclockwise) around a at, circular curve at constant speed, so that the left, front wheel traces out a circular path of radius R = 9:60 m. If the width of the car is 1:74 m, what is the ratio of the angular velocity about its axle of the left, front wheel to that of the right, front wheel, of the car as it moves through the curve? Assume the wheels roll without slipping.
2. A 3.0 cm thick layer of oil with density ρo = 800 kg/m3 is floating above water that has density ρw = 1000 kg/m3. A solid cylinder is floating so that 1/3 is in the water, 1/3 is in the oil, and 1/3 is in the air. Additional oil is added until the cylinder is fl oating only in oil. What fraction of the cylinder is in the oil?
3. An introductory physics student, elated by a first semester grade, celebrates by dropping a text-book from a balcony into a deep layer of soft snow which is 3.00 m below. Upon hitting the snow the book sinks a further 1.00 m into it before coming to a stop. The mass of the book is 5.0 kg. Assuming a constant retarding force, what is the force from the snow on the book?
4. A small bead slides from rest along a wire that is shaped like a vertical uniform helix (spring). Which graph below shows the magnitude of the acceleration a as a function of time? The following information applies to questions 5 and 6. 5. In the frame of the box, which of the following is a possible path followed by the particle? 6. If the magnitude of the acceleration of the box is chosen correctly, the launched particle will follow a path that returns to the point that it was launched. In the frame of the box, which path is followed by the particle? 7. A mass on a frictionless table is attached to the midpoint of an originally unstretched spring fixed at the ends. If the mass is displaced a distance A parallel to the table surface but perpendicular to the spring, it exhibits oscillations. The period T of the oscillations

8. Kepler's Laws state that

1. the orbits of planets are elliptical with one focus at the sun,
2. a line connecting the sun and a planet sweeps out equal areas in equal times, and
3. the square the period of a planet's orbit is proportional to the cube of its semi-major axis.

Which of these laws would remain true if the force of gravity were proportional to 1/r3 rather than 1/r2?
9. A small bead is placed on the top of a frictionless glass sphere of diameter D as shown. The bead is given a slight push and starts sliding down along the sphere. Find the speed v of the bead at the point at which the which the bead leaves the sphere.
10. Two blocks are suspended by two massless elastic strings to the ceiling as shown in the figure. The masses of the upper and lower block are m1 = 2 kg and m2 = 4 kg respectively. If the upper string is suddenly cut just above the top block what are the accelerations of the two blocks at the moment when the top block begins to fall?

11. The power output from a certain experimental car design to be shaped like a cube is proportional to the mass m of the car. The force of air friction on the car is proportional to Av2, where v is the speed of the car and A the cross sectional area. On a level surface the car has a maximum speed vmax. Assuming that all versions of this design have the same density, then which of the following is true? Related Documents