phys 211 midterm 3

pdf

School

University of Illinois, Urbana Champaign *

*We aren’t endorsed by this school

Course

211

Subject

Physics

Date

Apr 3, 2024

Type

pdf

Pages

10

Uploaded by ColonelFog484

Report
Physics 211 Fall 2022 November 2022 1) 2) HE3 2022 Fall (Not for credit) (Default) The next two questions pertain to the situation described below. A uniform solid cylinder having mass and radius is free to rotate around a fixed frictionless axle through its center (out of the page in the figure). The cylinder is initially at rest and at a constant torque with magnitude is applied around the axis causing the cylinder to rotate. How many revolutions has the cylinder made after seconds? a. b. c. d. e. Suppose the answer to the above problem is If the same cylinder is restarted from rest and the magnitude of the applied torque is doubled, how many turns would the cylinder make in half the time? a. b. c. The next three questions pertain to the situation described below. Assignment Set Tool https://smart.physics.illinois.edu/Course/SetTool?unitItemSetID=3731... 1 of 10 4/18/2023, 1:20 PM
3) 4) Two coaxial solid disks are glued together and placed on a common axle passing through the center of mass of the disks normal to their circular cross sections. A constant 50 N force F is applied at the rim of the larger disk by a string wound around its rim (the string is not shown in the figure). The string does not slip. The radii of the smaller and larger disks, and are 0.3 m and 0.5 meter, respectively, but the disks have identical masses M . The disks are initially at rest. At t = 0 the disks are allowed to rotate. How much work is done by the force applied to the rim of the larger disk between t = 0 and the time when the disks have completed one full revolution? a. 157.1 J b. 12.5 J c. 55 J d. 32.6 J e. not enough information to tell At the end of the first rotation, a force of constant magnitude is applied to the rim of the smaller disk, tangentially to the rim, to counteract the force applied to the larger disk. What should the magnitude of the second force be for the system of disks to maintain a constant angular velocity? a. 83.3 N b. 30 N c. 50 N Assignment Set Tool https://smart.physics.illinois.edu/Course/SetTool?unitItemSetID=3731... 2 of 10 4/18/2023, 1:20 PM
5) Now the system of disks is brought back to rest and the smaller disk is removed. (Recall that both disks have mass M and their radii are and .) The same force F is applied to the rim of the remaining disk as before. How does the angular acceleration of the larger disk alone, , relate to the angular acceleration of the system of two disks, ,measured previously? a. b. c. d. e. Assignment Set Tool https://smart.physics.illinois.edu/Course/SetTool?unitItemSetID=3731... 3 of 10 4/18/2023, 1:20 PM
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
  • Access to all documents
  • Unlimited textbook solutions
  • 24/7 expert homework help
6) 7) The next two questions pertain to the situation described below. A hoop-shaped space station is initially at rest in outer space. The mass of the space station is kg and its radius is m. The station's chief engineer decides to generate artificial gravity to make life easier for the crew. She starts the rotation of the space station by firing three rockets evenly spaced on the outer edge of the hoop, as shown. Each rocket provides a tangential force of magnitude , causing the space station to start rotating around an axis through its center with a constant angular acceleration rad/s . What is the magnitude of the force provided by each of the rockets? a. 9.72 × 10 N b. 3.24 × 10 N c. 16200 N d. 5400 N e. 2700 N What is the angular velocity of the space station after it has made one complete revolution ? a. 0.053 rad/s b. 0.106 rad/s c. 0.03 rad/s d. 0.011 rad/s e. 0.075 rad/s 5 5 Assignment Set Tool https://smart.physics.illinois.edu/Course/SetTool?unitItemSetID=3731... 4 of 10 4/18/2023, 1:20 PM
8) 9) 10) The next three questions pertain to the situation described below. A solid ball (sphere) of radius R = 16 cm and mass M = 600 g has string wound around its circumference. It is hung from a ceiling and released from rest as shown in the diagram with the string taut and vertical. What is the acceleration of the solid sphere? a. 5.89 m/s b. 6.54 m/s c. 9.81 m/s d. 13.73 m/s e. 7.01 m/s Consider that the string unwinds from the solid sphere (initially at rest) such that the sphere falls by a distance of 40 cm. Compare the total kinetic energy of the sphere in this case ( ) to the total kinetic energy the sphere would have if it simply fell by an equivalent distance with no string attached at all ( ): a. b. c. Consider again the first problem in this set. If you replace the solid ball (sphere) with a solid disk having the same mass and radius, then how would the acceleration of the solid disk compare to the acceleration of the solid ball? a. The acceleration of the disk would be larger than that of the ball. b. The accelerations of the disk and the ball would be the same. c. The acceleration of the disk would be smaller than that of the ball. Assignment Set Tool https://smart.physics.illinois.edu/Course/SetTool?unitItemSetID=3731... 5 of 10 4/18/2023, 1:20 PM
11) 12) 13) 14) The next four questions pertain to the situation described below. A beam has mass 0.18 kg and length 1.7 m and hangs vertically at rest below a fixed frictionless pivot. A projectile with initial horizontal velocity 3.5 m/s and mass collides with and sticks to the bottom of the beam. Immediately after the collision the angular velocity of the beam is The beam (with the projectile stuck to the bottom) swings upward, reaches some maximum height, then swings back and forth. What is the angular momentum of the projectile about the pivot when it is a distance to the left of the beam (as shown in the before collision image)? a. 0.357 kg m/s b. 0.161 kg m/s c. 0.21 kg m/s Which quantities are conserved during the collision between the beam and the projectile? a. Angular momentum but not total mechanical energy. b. Total mechanical energy but not angular momentum. c. Both angular momentum and total mechanical energy. What is the angular velocity of the beam just after the collision ? a. = 1.03 rad/s b. = 2.06 rad/s c. = 4.12 rad/s Which quantities are conserved after the collision, while the beam swings back and forth ? a. Total mechanical energy but not angular momentum. b. Angular momentum but not total mechanical energy. c. Both angular momentum and total mechanical energy. 2 Assignment Set Tool https://smart.physics.illinois.edu/Course/SetTool?unitItemSetID=3731... 6 of 10 4/18/2023, 1:20 PM
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
  • Access to all documents
  • Unlimited textbook solutions
  • 24/7 expert homework help
15) 16) 17) The next three questions pertain to the situation described below. A gyroscope made from a solid disk of mass M = 6.1 kg and radius R = 0.42 m hangs from a rope attached to the ceiling. The disk spins around a horizontal axle through its center in the direction shown by the arrow, and the rope is attached to one end of this axle at a distance D = 1.33 m from the disk. The angular momentum of the disk is L = 55.9 kg-m /s. What is the magnitude of the angular velocity of the spinning disk? a. = 312 rad/s b. = 104 rad/s c. = 249 rad/s d. = 125 rad/s e. = 156 rad/s If viewed by somone looking down on the gyroscope from above, which way does it precess? a. Clockwise. b. Counterclockwise. c. There is not enough information given to determine this. What is the period of the precession of the gyroscope (in other words, the time needed to make one complete revolution in the horizontal plane) ? a. = 4.41 s b. = 1.42 s c. = 0.7 s d. = 2.21 s e. = 13.97 s 2 Assignment Set Tool https://smart.physics.illinois.edu/Course/SetTool?unitItemSetID=3731... 7 of 10 4/18/2023, 1:20 PM
18) 19) 20) 21) The next four questions pertain to the situation described below. A beam of mass m and length L is hinged and extends outward perpendicular to a wall, as shown. A string is attached to the end of the beam with its other end attached to the wall a distance L/3 above the hinge; the tension in that string is T = 110 N. A mass M = 2.4 kg hangs a distance L/4 from the end of the beam. What is the mass, m, of the beam? a. 1 kg b. 6.3 kg c. Cannot be determined unless a value for L is provided d. 17.7 kg e. 3.5 kg What is the x-component of the force exerted by the hinge on the beam? a. 34.8 N b. 104.4 N c. 73.3 N d. 55 N e. Cannot be determined unless a value for L is provided Suppose that the string is now attached higher at a distance of L/2 above the hinge and the tension adjusts (it is no longer 110 N) so that the set- up remains in equilibrium. How would the x-component of the force exerted by the hinge on the beam change from previously? a. It would increase b. It would decrease c. It would remain the same Now suppose that the string is cut from the original situation at the top of the page. In terms of m, M, g and L, which expression below is correct for the angular acceleration of the beam about the hinge immediately after the string is cut? a. b. c. d. e. Assignment Set Tool https://smart.physics.illinois.edu/Course/SetTool?unitItemSetID=3731... 8 of 10 4/18/2023, 1:20 PM
22) 23) 24) The next three questions pertain to the situation described below. A ladder of length = 3 meters and mass = 15 kg leans on a wall at an angle of = 45 degrees. The coefficient of friction between the floor and the ladder is . There is no friction between the ladder and the wall. A man of mass = 70 kg climbs a distance d up the ladder. Which diagram best represents the free body diagram of the ladder? a. Diagram (i) b. Diagram (ii) c. Diagram (iii) What is the minimum value of that would allow the man to climb to the top of the ladder? a. 0.41 b. 0.64 c. 0.82 d. 0.35 e. 0.91 What happens to the minimum value of in the previous question if the becomes slightly larger? a. it decreases b. it increases c. it remains the same Assignment Set Tool https://smart.physics.illinois.edu/Course/SetTool?unitItemSetID=3731... 9 of 10 4/18/2023, 1:20 PM
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
  • Access to all documents
  • Unlimited textbook solutions
  • 24/7 expert homework help
25) 26) The next two questions pertain to the situation described below. A solid sphere, a hollow sphere, and a solid cylinder have the same mass M and the same radius R. They are positioned at the top of the same ramp at the same height h = 6.6 m. They are released from rest and roll down the ramp without slipping. Which object has the largest velocity when it reaches the bottom of the ramp? a. The solid sphere. b. The hollow sphere. c. The solid cylinder. d. All three objects have the same velocity at the bottom of the ramp. e. The answer cannot be determined with the information provided. What is the velocity of the solid sphere when it reaches the bottom of the ramp, ? a. = 11.38 m/s b. = 9.62 m/s c. = 8.05 m/s d. = 8.81 m/s e. = 12.72 m/s Assignment Set Tool https://smart.physics.illinois.edu/Course/SetTool?unitItemSetID=3731... 10 of 10 4/18/2023, 1:20 PM

Related Documents

phys 223 lab 4 report.docx
quiz1-practice.pdf
Lab 8 Wilkinson copy.docx
Lab 8 Wilkinson.docx
Phys 132 Lab 1.pdf
lab 14.pdf
The Simple Pendulum_Hypothesis Testing_PHYS 130.docx
M06 PBS Technology Assignment.docx
Doppler_Effect_WS__Key.pdf
Clarin Lab 2 bowling ball and air track motion-1.docx.pdf
Yuchan Make-Up Lab for Lab 2_ Paper Drop - Notebook.pdf
Lab 3 & 4 Cratering Parts 1 and 2 - Notebook Template.pdf
Recommended textbooks for you
Text book image
Physics for Scientists and Engineers
Physics
ISBN:9781337553278
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
Text book image
Physics for Scientists and Engineers with Modern ...
Physics
ISBN:9781337553292
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
Text book image
Physics for Scientists and Engineers: Foundations...
Physics
ISBN:9781133939146
Author:Katz, Debora M.
Publisher:Cengage Learning
Text book image
Principles of Physics: A Calculus-Based Text
Physics
ISBN:9781133104261
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
Text book image
Classical Dynamics of Particles and Systems
Physics
ISBN:9780534408961
Author:Stephen T. Thornton, Jerry B. Marion
Publisher:Cengage Learning
Text book image
College Physics
Physics
ISBN:9781938168000
Author:Paul Peter Urone, Roger Hinrichs
Publisher:OpenStax College
SEE MORE TEXTBOOKS
Recommended textbooks for you
Text book image
Physics for Scientists and Engineers
Physics
ISBN:9781337553278
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
Text book image
Physics for Scientists and Engineers with Modern ...
Physics
ISBN:9781337553292
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
Text book image
Physics for Scientists and Engineers: Foundations...
Physics
ISBN:9781133939146
Author:Katz, Debora M.
Publisher:Cengage Learning
Text book image
Principles of Physics: A Calculus-Based Text
Physics
ISBN:9781133104261
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
Text book image
Classical Dynamics of Particles and Systems
Physics
ISBN:9780534408961
Author:Stephen T. Thornton, Jerry B. Marion
Publisher:Cengage Learning
Text book image
College Physics
Physics
ISBN:9781938168000
Author:Paul Peter Urone, Roger Hinrichs
Publisher:OpenStax College
SEE MORE TEXTBOOKS