
Concept explainers
At t = 0 a cooling fan running at 200 rad/s is turned off and then slows down at a rate of 20 rad/s2. Simultaneously (at t = 0) a second cooling fan is turned on and begins to spin from rest with an acceleration of 60 rad/s2. (a) Find the time at which both fans have the same angular speed. (b) What is the angular speed of the fans at this time?

Want to see the full answer?
Check out a sample textbook solution
Chapter 9 Solutions
College Physics Volume 1 (Chs. 1-16); Mastering Physics with Pearson eText -- ValuePack Access Card -- for College Physics (10th Edition)
Additional Science Textbook Solutions
Chemistry: The Central Science (14th Edition)
Biology: Life on Earth (11th Edition)
Microbiology: An Introduction
Human Anatomy & Physiology (2nd Edition)
Biology: Life on Earth with Physiology (11th Edition)
Physics for Scientists and Engineers: A Strategic Approach, Vol. 1 (Chs 1-21) (4th Edition)
- Small ice cubes, each of mass 5.60 g, slide down a frictionless track in a steady stream, as shown in the figure below. Starting from rest, each cube moves down through a net vertical distance of h = 1.50 m and leaves the bottom end of the track at an angle of 40.0° above the horizontal. At the highest point of its subsequent trajectory, the cube strikes a vertical wall and rebounds with half the speed it had upon impact. If 10 cubes strike the wall per second, what average force is exerted upon the wall? N ---direction--- ▾ ---direction--- to the top to the bottom to the left to the right 1.50 m 40.0°arrow_forwardThe magnitude of the net force exerted in the x direction on a 3.00-kg particle varies in time as shown in the figure below. F(N) 4 3 A 2 t(s) 1 2 3 45 (a) Find the impulse of the force over the 5.00-s time interval. == N⚫s (b) Find the final velocity the particle attains if it is originally at rest. m/s (c) Find its final velocity if its original velocity is -3.50 î m/s. V₁ m/s (d) Find the average force exerted on the particle for the time interval between 0 and 5.00 s. = avg Narrow_forward••63 SSM www In the circuit of Fig. 27-65, 8 = 1.2 kV, C = 6.5 µF, R₁ S R₂ R3 800 C H R₁ = R₂ = R3 = 0.73 MQ. With C completely uncharged, switch S is suddenly closed (at t = 0). At t = 0, what are (a) current i̟ in resistor 1, (b) current 2 in resistor 2, and (c) current i3 in resistor 3? At t = ∞o (that is, after many time constants), what are (d) i₁, (e) i₂, and (f) iz? What is the potential difference V2 across resistor 2 at (g) t = 0 and (h) t = ∞o? (i) Sketch V2 versus t between these two extreme times. Figure 27-65 Problem 63.arrow_forward
- Thor flies by spinning his hammer really fast from a leather strap at the end of the handle, letting go, then grabbing it and having it pull him. If Thor wants to reach escape velocity (velocity needed to leave Earth’s atmosphere), he will need the linear velocity of the center of mass of the hammer to be 11,200 m/s. Thor's escape velocity is 33532.9 rad/s, the angular velocity is 8055.5 rad/s^2. While the hammer is spinning at its maximum speed what impossibly large tension does the leather strap, which the hammer is spinning by, exert when the hammer is at its lowest point? the hammer has a total mass of 20.0kg.arrow_forwardIf the room’s radius is 16.2 m, at what minimum linear speed does Quicksilver need to run to stay on the walls without sliding down? Assume the coefficient of friction between Quicksilver and the wall is 0.236.arrow_forwardIn the comics Thor flies by spinning his hammer really fast from a leather strap at the end of the handle, letting go, then grabbing it and having it pull him. If Thor wants to reach escape velocity (velocity needed to leave Earth’s atmosphere), he will need the linear velocity of the center of mass of the hammer to be 11,200 m/s. A) If the distance from the end of the strap to the center of the hammer is 0.334 m, what angular velocity does Thor need to spin his hammer at to reach escape velocity? b) If the hammer starts from rest what angular acceleration does Thor need to reach that angular velocity in 4.16 s? c) While the hammer is spinning at its maximum speed what impossibly large tension does the leather strap, which the hammer is spinning by, exert when the hammer is at its lowest point? The hammer has a total mass of 20.0kg.arrow_forward
- The car goes from driving straight to spinning at 10.6 rev/min in 0.257 s with a radius of 12.2 m. The angular accleration is 4.28 rad/s^2. During this flip Barbie stays firmly seated in the car’s seat. Barbie has a mass of 58.0 kg, what is her normal force at the top of the loop?arrow_forwardConsider a hoop of radius R and mass M rolling without slipping. Which form of kinetic energy is larger, translational or rotational?arrow_forwardA roller-coaster vehicle has a mass of 571 kg when fully loaded with passengers (see figure). A) If the vehicle has a speed of 22.5 m/s at point A, what is the force of the track on the vehicle at this point? B) What is the maximum speed the vehicle can have at point B, in order for gravity to hold it on the track?arrow_forward
- This one wheeled motorcycle’s wheel maximum angular velocity was about 430 rev/min. Given that it’s radius was 0.920 m, what was the largest linear velocity of the monowheel?The monowheel could not accelerate fast or the rider would start spinning inside (this is called "gerbiling"). The maximum angular acceleration was 10.9 rad/s2. How long, in seconds, would it take it to hit maximum speed from rest?arrow_forwardIf points a and b are connected by a wire with negligible resistance, find the magnitude of the current in the 12.0 V battery.arrow_forwardConsider the two pucks shown in the figure. As they move towards each other, the momentum of each puck is equal in magnitude and opposite in direction. Given that v kinetic energy of the system is converted to internal energy? 30.0° 130.0 = green 11.0 m/s, and m blue is 25.0% greater than m 'green' what are the final speeds of each puck (in m/s), if 1½-½ t thearrow_forward
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningPrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningUniversity Physics Volume 1PhysicsISBN:9781938168277Author:William Moebs, Samuel J. Ling, Jeff SannyPublisher:OpenStax - Rice University
- Glencoe Physics: Principles and Problems, Student...PhysicsISBN:9780078807213Author:Paul W. ZitzewitzPublisher:Glencoe/McGraw-HillCollege PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage LearningCollege PhysicsPhysicsISBN:9781938168000Author:Paul Peter Urone, Roger HinrichsPublisher:OpenStax College





