College Physics A Strategic Approach 2nd Edition by Knight) Calculate the angular speed, in rad/s of a flywheel turning at 520.0 rpm. 54. A) 54.44 rad/s
... [Show More] 55. B) 8.656 rad/s 56. C) 40.83 rad/s 57. D) 60.97 rad/s Contact: [email protected] Answer: A Var: 50+ 2) Through what angle in degrees does a 33 rpm record turn in 0.25 s? 1. A) 50° 2. B) 28° 3. C) 36° 4. D) 58° Answer: A Var: 26 3) An electrical motor spins at a constant 2857.0 rpm. If the armature radius is 2.685 cm, what is the acceleration of the edge of the rotor? 1. A) 2403 m/s2 2. B) 844.4 m/s2 3. C) 241,100 m/s2 4. D) 84.40 m/s2 Answer: A Var: 50+ 4) A satellite is in orbit around a planet. The orbital radius is 34.0 km and the gravitational acceleration at that height is 2.3 m/s2. What is the satellite’s orbital speed? 1. A) 280 m/s 2. B) 8.8 m/s 3. C) 28 m/s 4. D) 88 m/s Answer: A Var: 50+ 5) A 23 kg mass is connected to a nail on a frictionless table by a (massless) string of length 1.3 m. If the tension in the string is 51 N while the mass moves in a uniform circle on the table, how long does it take for the mass to make one complete revolution? 4. A) 4.8 s 5. B) 3.8 s 6. C) 4.5 s 7. D) 5.2 s Answer: A Var: 50+ 6) A new roller coaster contains a loop-the-loop in which the car and rider are completely upside down. If the radius of the loop is 13.2 m, with what minimum speed must the car traverse the loop so that the rider does not fall out while upside down at the top? Assume the rider is not strapped to the car. 11. A) 11.4 m/s 12. B) 12.5 m/s 13. C) 10.1 m/s 14. D) 14.9 m/s Answer: A Var: 50+ 7) A tetherball is on a 2.1 m string that makes an angle of 44° with the vertical as it moves around the pole in a horizontal plane. If the mass of the ball is 1.3 kg, what is the ball’s speed? 3. A) 3.7 m/s 4. B) 2.9 m/s 5. C) 3.4 m/s 6. D) 4.2 m/s Answer: A Var: 50+ 8) In an amusement park ride, passengers stand inside an 8 m radius cylinder. Initially, the cylinder rotates with its axis oriented along the vertical. After the cylinder has acquired sufficient speed, it tilts into a vertical plane, that is, the axis tilts into the horizontal, as shown in the figure. Suppose that, once the axis has tilted into the horizontal, the ring rotates once every 4.5 s. If a rider’s mass is 40 kg, with how much force does the ring push on her at the top of the ride? 1. A) 230 N 2. B) 620 N 3. C) 1000 N 4. D) 390 N Answer: A Var: 50+ 9) Future space stations will create an artificial gravity by rotating. Consider a cylindrical space station of 380 m diameter rotating about its axis. Astronauts walk on the inside surface of the space station. What rotation period will provide “normal” gravity? 1. A) 28 s 2. B) 39 s 3. C) 6.2 s 4. D) 4.4 s Answer: A Var: 50+ 10) An aerobatic aircraft is to perform a spiral maneuver. If the engine provides a tangential acceleration of 5.41 m/s2, what is the radial acceleration it will experience at the end of a circle 30.8 m in radius, if the speed at the beginning of the stunt was 55.0 m/s? 1. A) 166 m/s2 2. B) 132 m/s2 3. C) 98 m/s2 4. D) 257 m/s2 Answer: A Var: 50+ 11) A ball of mass 8.0 kg is suspended by two wires from a horizontal arm, which is attached to a vertical shaft, as shown in the figure. The shaft is in uniform rotation about its axis such that the linear speed of the ball equals 2.3 m/s. The tension in wire 1 is closest to: 1. A) 39 N 2. B) 49 N 3. C) 29 N 4. D) 20 N 5. E) 9.8 N Answer: A Var: 50+ 12) The figure shows two wires tied to a 3.3 kg sphere that revolves in a horizontal circle at constant speed. At this particular speed the tension is the same in both wires. What is the tension? 1. A) 24 N 2. B) 32 N 3. C) 44 N 4. D) 22 N Answer: A Var: 50+ 13) The figure shows two wires that are tied to a 710 g mass that revolves in a horizontal circle at a constant speed of 7.5 m/s. What is the tension in the upper wire? 1. A) 34 N 2. B) 20 N 3. C) 27 N 4. D) 41 N Answer: A Var: 50+ 14) A 90 g bead on a 60 cm long string is swung in a vertical circle about a point 200 cm above the floor. The tension in the string when the bead is at the very bottom of the circle is 2.2 N. A very sharp knife is suddenly inserted, as shown in the figure, to cut the string directly below the point of support. How far to the right of the center of the circle does the ball hit the floor? [Show Less]