PHYS 101-4M, Fall 2005 Exam #3 Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) A bicycle wheel rotates uniformly through 2.0 revolutions in 4.0 s. What is the frequency of the wheel's rotation? A) 1.0 Hz B) 0.50 Hz C) 2.0 Hz D) 4.0 Hz 2) A mass on a spring undergoes SHM. When the mass passes through the equilibrium position, its instantaneous velocity A) is less than maximum, but not zero. B) is maximum. C) is zero. D) cannot be determined from the information given. 3) A 500-N weight sits on the small piston of a hydraulic machine. The small piston has area 2.0 cm2. If the large piston has area 40 cm2, how much weight can the large piston support? A) 40000 N B) 500 N C) 10000 N D) 25 N 4) A wheel accelerates with a constant angular acceleration of 4.5 rad/s2. If the initial angular velocity is 1.0 rad/s, what is the angle the wheel rotates through in 2.0 s? A) 11 rad B) 4.5 rad C) 7.0 rad D) 9.0 rad 5) For vibrational motion, the maximum displacement from the equilibrium point is called the A) amplitude. B) period. C) wavelength. D) frequency. 6) A wheel of radius 1.0 m is rotating with a constant angular speed of 2.0 rad/s. What is the linear speed of a point on the wheel's rim? A) 1.0 m/s B) 0.50 m/s C) 4.0 m/s D) 2.0 m/s 7) A boy and a girl are riding on a merry-go-round which is turning at a constant rate. The boy is near the outer edge, and the girl is closer to the center. Who has the greater angular velocity? C) Both have the same non-zero angular velocity. D) Both have zero angular velocity. 8) A mass on a spring undergoes SHM. It goes through 10 complete oscillations in 5.0 s. What is the period? A) 0.50 s B) 0.020 s C) 50 s D) 2.0 s 9) The time for one cycle of a periodic process is called the A) frequency. B) amplitude. C) wavelength. D) period. 10) The bolts on a car wheel require tightening to a torque of 90 Nœm. If a 30 cm long wrench is used, what is the magnitude of the force required when the force is perpendicular to the wrench? A) 30 N B) 300 N C) 150 N D) 15 N 1) 2) 3) 4) 5) 6) 7) 8) 9) 10) 1
11) A block of metal weighs 40 N in air and 30 N in water. What is the buoyant force of the water? A) 40 N B) 70 N C) 10 N D) 30 N 11) 12) A circular window of 30 cm diameter in a submarine can withstand a maximum force of 5.20 105 N. What is the maximum depth in a lake to which the submarine can go without damaging the window? (The density of water is 1000 kg/m3.) A) 1327 m B) 1200 m C) 750 m D) 680 m 12) 13) A boy and a girl are riding on a merry-go-round which is turning at a constant rate. The boy is near the outer edge, and the girl is closer to the center. Who has the greater angular displacement? 13) C) Both have the same non-zero angular displacement. D) Both have zero angular displacement. 14) If a constant net torque is applied to an object, that object will A) having a decreasing moment of inertia. B) having an increasing moment of inertia. C) rotate with constant angular velocity. D) rotate with constant angular acceleration. 14) 15) A wheel of radius 1.0 m is rotating with a constant angular speed of 2.0 rad/s. What is the centripetal acceleration of a point on the wheel's rim? A) 2.0 m/s2 B) 1.0 m/s2 C) 4.0 m/s2 D) 0.50 m/s2 15) 16) What is the velocity of a wave that has a wavelength of 3.0 m and a frequency of 12 Hz? A) 9.0 m/s B) 15 m/s C) 4.0 m/s D) 36 m/s 16) 17) What is the pressure at a location 15.0 m below the surface of sea? (The density of seawater is 1.03 103 kg/m3.) A) 2.52 105 N/m2 B) 1.51 105 N/m2 C) 1.24 105 N/m2 D) 1.01 105 N/m2 17) 18) Consider three drinking glasses. All three have the same area base, and all three are filled to the same depth with water. Glass A is cylindrical. Glass B is wider at the top than at the bottom, and so holds more water than A. Glass C is narrower at the top than at the bottom, and so holds less water than A. Which glass has the greatest liquid pressure at the bottom? 18) A) Glass A B) Glass B C) Glass C D) All three have equal pressure. 19) A wheel accelerates with a constant angular acceleration of 4.5 rad/s2. If the initial angular velocity is 1.0 rad/s, what is the angular velocity at t = 2.0 s? 19) A) 1.0 rad/s B) 7.0 rad/s C) 10 rad/s D) 9.0 rad/s 20) Angular velocity is expressed in units of A) omegas per second. B) meters per second. C) arcs per second. D) radians per second. 20) 2
21) A mass is attached to a vertical spring and bobs up and down between points A and B. Where is the mass located when its potential energy is a maximum? A) midway between A and B B) at either A or B C) one-fourth of the way between A and B D) none of the above 21) 22) The distance between successive crests on a wave is called the wave's A) amplitude. B) speed. C) wavelength. D) frequency. 22) 23) A boy and a girl are riding on a merry-go-round which is turning at a constant rate. The boy is near the outer edge, and the girl is closer to the center. Who has the greater linear speed? C) Both have the same non-zero translational velocity. D) Both have zero translational velocity. 23) 24) A wheel with moment of inertia 3.00 kgœm2 has a net torque of 3.50 Nœm applied to it. What angular acceleration does it experience? A) 0.857 rad/s2 B) 3.00 rad/s2 C) 1.17 rad/s2 D) 3.50 rad/s2 24) 25) How many rad/s is 25 revolutions per minute equivalent to? A) 0.42 rad/s B) 240 rad/s C) 160 rad/s D) 2.6 rad/s 25) 26) Two forces produce the same torque. Does it follow that the forces have the same magnitude? A) Yes B) No 26) 27) A 0.50-kg mass is attached to a spring of spring constant 20 N/m along a horizontal, frictionless surface. The object oscillates in simple harmonic motion and has a speed of 1.5 m/s at the equilibrium position. What is the total energy of the system? A) 0.65 J B) 1.1 J C) 0.56 J D) 0.27 J 27) 28) Two spheres have the same radius and equal masses. One is made of solid aluminum, and the other is made from a hollow shell of gold. Which one has the bigger moment of inertia about an axis through its center? A) Solid aluminum B) Hollow gold C) same 28) 3
FIGURE 11-2 29) Figure 11-2 is a "snapshot" of a wave at a given time. The frequency of the wave is 120 Hz. What is the wavelength? 29) A) 0.30 m B) 0.05 m C) 0.20 m D) 0.10 m 30) Figure 11-2 is a "snapshot" of a wave at a given time. The frequency of the wave is 120 Hz. What is the amplitude? 30) A) 0.20 m B) 0.10 m C) 0.15 m D) 0.05 m 31) Two wave pulses pass each other on a string. The one traveling toward the right has a positive amplitude, while the one traveling toward the left has an equal amplitude in the negative direction. At the point that they occupy the same region of space at the same time 31) A) the two waves stop. B) the resultant wave has a negative amplitude equal to the amplitude of one wave. C) the resultant wave has twice the amplitude of the waves. D) the resultant wave has zero amplitude. 32) For a wave, the frequency times the wavelength is the wave's A) speed. B) intensity. C) power. D) amplitude. 32) 33) A wheel starts at rest, and has an angular acceleration of 4 rad/s2. Through what angle does it turn in 3.0 s? 33) A) 9.0 rad B) 36 rad C) 12 rad D) 18 rad 34) A 4.0-kg object is attached to a spring of spring constant 10 N/m. The object is displaced by 5.0 cm from the equilibrium position and let go. What is the period of vibration? 34) A) 8.0 s B) 2.0 s C) 4.0 s D) 16 s 35) A person weighing 900 N is standing on snowshoes. Each snowshoe has area 2500 cm2. What is the pressure on the snow? A) 1800 N/m2 B) 3600 N/m2 C) 0.18 N/m2 D) 0.36 N/m2 35) 36) An object has a volume of 4.0 m3 and weighs 40,000 N. What will its weight be in water? (The density of water is 1000 kg/m3.) A) 39,200 N B) 40,000 N C) 800 N D) 9,800 N 36) 4
Answer Key Testname: EXAM4_CH8_10_11 1) B 2) B 3) C 4) A 5) A 6) D 7) C 8) A 9) D 10) B 11) C 12) C 13) C 14) D 15) C 16) D 17) B 18) D 19) C 20) D 21) B 22) C 23) B 24) C 25) D 26) B 27) C 28) B 29) C 30) B 31) D 32) A 33) D 34) C 35) A 36) C 5