027 100points the speedometer in a vehicle is

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027 10.0points The speedometer in a vehicle is configured to read speed proportional to the rotational speed of its wheels. If larger wheels, such as those of snow tires, are used, what will be the effect on the speedometer reading? 1. The speedometer reads a lower speed than the vehicle is moving 2. The speedometer reads a higher speed than the vehicle is moving 3. The speedometer shows correctly the speed at which the vehicle is moving 028 10.0points A wheel starts from rest and has an angular acceleration of 4 rad / s 2 . When it has made 10 revolutions, its angu- lar velocity is about: 1. 16 rad / s 2. 500 rad / s 3. 22 rad / s 4. 32 rad / s 5. 250 rad / s 029 10.0points In a mixture of hydrogen and oxygen gases at the same temperature, which molecules move faster and why? 1. Oxygen molecules will move faster; they have a larger average kinetic energy. 2. Hydrogen molecules will move faster; they have a larger average kinetic energy. 3. Hydrogen molecules will move faster; the mass of hydrogen is less than that of oxygen. 4. They have the same average speed be- cause they have the same average kinetic en- ergy. 030 10.0points A mass 3 m collides head-on with a mass m . Before the collision the masses are moving directly toward one another with the same speed v 0 . v 0 v 0 3 m m After the collision, the mass 3 m is moving
douglas (jed3339) – Practice Final – yao – (56695) 7 in its original direction at speed v 0 2 . v 0 2 v 3 m m What is the speed v of the mass m after the collision? 1. v = 3 v 0 2. v = 0 3. v = v 0 4. v = v 0 3 5. v = v 0 2 6. v = 2 v 0 7. v = 4 v 0 8. v = 2 v 0 3
siddiqui (uas88) – Practice Midterm 03 – yao – (56725) 1 This print-out should have 15 questions. Multiple-choice questions may continue on the next column or page – find all choices before answering. 001 10.0points A simple harmonic oscillator consists of a mass on a horizontal spring, oscillating with an amplitude A and negligible friction. What is the distance of the mass to the equilibrium position ( x = 0) at the instant when the kinetic and potential energies are equal? 1. 0 2. A 2 correct 3. A 2 4. A Explanation: For a simple harmonic oscillator, the total mechanical energy is 1 2 k A 2 . When the ki- netic and potential energies are equal, half of the total mechanical energy is potential en- ergy. This must occur at | x | = A 2 , since the potential energy varies as the square of the distance of the mass to the equilibrium position. 002 10.0points A small puck moves in a circle on a frictionless airtable. The circular motion is enforced by string tied to the puck and going through a tiny hole in the middle of the table. Initially, the puck moves in a circle of radius R 1 at angular velocity ω 1 . But later the string is pulled down through the hole forcing the puck to move in a smaller circle of radius R 2 = 1 2 R 1 . R ω What is the new angular velocity of the puck ω 2 ?

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