8. A solid wooden door, 90 cm wide by 2.0 m tall, has a mass of 35 kg. It is open and at rest. A small 500-g ball is thrown perpendicular to the door with a speed of 20 m/s and hits the door 60 cm from the hinged side, causing it to begin turning. The ball rebounds along the same line with a speed of 16.00 m/s relative to the ground If the momentum of inertia of the door around the hinge is I-1/3 Ma2, where a is the width of the door, how much energy was lost during this collision? A) 30 J B) 16 J C) 15 J D) 13 J E) 4.8 J

8. A solid wooden door, 90 cm wide by 2.0 m tall, has a mass of 35 kg. It is open and at rest. A small 500-g ball is thrown perpendicular to the door with a speed of 20 m/s and hits the door 60 cm from the hinged side, causing it to begin turning. The ball rebounds along the same line with a speed of 16.00 m/s relative to the ground If the momentum of inertia of the door around the hinge is I-1/3 Ma2, where a is the width of the door, how much energy was lost during this collision? A) 30 J B) 16 J C) 15 J D) 13 J E) 4.8 J

Physics for Scientists and Engineers: Foundations and Connections

1st Edition

ISBN:9781133939146

Author:Katz, Debora M.

Publisher:Katz, Debora M.

Chapter13: Rotation Ii: A Conservation Approach

Section: Chapter Questions

Problem 45PQ: A thin rod of length 2.65 m and mass 13.7 kg is rotated at anangular speed of 3.89 rad/s around an...

See similar textbooks

Similar questions

A propeller consists of two blades each 3.0 m in length and mass 120 kg each. The propeller can be approximated by a single rod rotating about its center of mass. The propeller starts from rest and rotates up to 1200 rpm in 30 seconds at a constant rate. (a) What is the angular momentum of the propeller at t=10s ; t=20s ? (b) What is the torque on the propeller?
A buzzard (m = 9.29 kg) is flying in circular motion with aspeed of 8.44 m/s while viewing its meal below. If the radius ofthe buzzards circular motion is 8.00 m, what is the angularmomentum of the buzzardaround the center of its motion?
A wooden block of mass M resting on a frictionless, horizontal surface is attached to a rigid rod of length and of negligible mass (Fig. P11.27). The rod is pivoted at the other end. A bullet of mass m traveling parallel to the horizontal surface and perpendicular to the rod with speed v hits the block and becomes embedded in it. (a) What is the angular momentum of the bulletblock system about a vertical axis through the pivot? (b) What fraction of the original kinetic energy of the bullet is converted into internal energy in the system during the collision? Figure P11.27
A wad of sticky clay with mass m and velocity vi is fired at a solid cylinder of mass M and radius R (Fig. P11.29). The cylinder is initially at rest and is mounted on a fixed horizontal axle that runs through its center of mass. The line of motion of the projectile is perpendicular to the axle and at a distance d R from the center. (a) Find the angular speed of the system just after the clay strikes and sticks to the surface of the cylinder. (b) Is the mechanical energy of the claycylinder system constant in this process? Explain your answer. (c) Is the momentum of the claycylinder system constant in this process? Explain your answer. Figure P11.29
Consider an isolated system moving through empty space. The system consists of objects that interact with each other and can change location with respect to one another. Which of the following quantities can change in time? (a) The angular momentum of the system. (b) The linear momentum of the system, (c) Both the angular momentum and linear momentum of the system, (d) Neither the angular momentum nor linear momentum of the system.
A thin rod of length 2.65 m and mass 13.7 kg is rotated at anangular speed of 3.89 rad/s around an axis perpendicular to therod and through its center of mass. Find the magnitude of therods angular momentum.
One end of a massless rigid rod of length is attached to a woodenblock of mass M restingon a frictionless, horizontal tabletop, and theother end is attached tothe table through apivot (Fig. P13.75). Abullet of mass m traveling with a speed v in adirection perpendicular to the rod and parallel to the table impacts the block and embeds itself inside. a. What is the angular momentum of this systemaround a vertical axis through the pivot after the collision?b. What is the fraction of the bullets initial kinetic energy thatis lost to internal energy duringthe collision? FIGURE P13.75
2.50 kg particle that is moving horizontally over a floor with velocity (-3.00 m/s)ˆj undergoes a completely inelastic collision with a 4.00 kg particle that is moving horizontally over the floor with velocity (4.50 m/s)iˆ. The collision occurs at xy coordinates (-0.500 m, -0.100 m). After the collision and in unit-vector notation, what is the angular momentum of the stuck-together particles with respect to the origin?
Candace is a 53 kg diver. At the instant of takeoff, her angular momentum about her transverse axis is 20 kg.m7s. Her radius of gyration about the transverse axis is 0.4 m at this instant. During the dive, Candace tucks and reduces her radius of gyration about thetransverse axis to 0.18 m.a) At takeoff, what is Candace's moment of inertia about her transverse axis? kg*m?b) At takeoff, what is Candace's angular velocity in degrees/sec about the transverse axis?c) After Candace tucks, what is her moment of inertia about her transverse axis? kg*m? d) After Candace tucks, what is her angular velocity in degrees/sec about the transverse axis?
As part of a carnival game, a Mb=0.478 kg ball is thrown at a stack of 17.3 cm tall, ?o=0.343 kg objects and hits with a perfectly horizontal velocity of ?b,i=11.8 m/s. Suppose that the ball strikes the topmost object. Immediately after the collision, the ball has a horizontal velocity of ?b,f=5.10 m/s in the same direction, the topmost object has an angular velocity of ωo=2.03 rad/s about its center of mass, and all the remaining objects are undisturbed. Assume that the ball is not rotating and that the effect of the torque due to gravity during the collision is negligible. If the object's center of mass is located r=12.1 cm below the point where the ball hits, what is the moment of inertia ?oIo of the object about its center of mass?
A diver (m = 60 kg) jumps from a diving board. At takeoff, his angular momentum about the transverse axis is 30 kg⋅m2/s. His radius of gyration about the transverse axis is 0.5 m at this instant. During the dive, he tucks and reduces his radius of gyrations about the transverse axis to 0.2 m. After he tucks the body, what is his angular velocity about the transverse axis?
A 45 kg figure skater is spinning on the toes of her skates at 0.50 rev/s. Her arms are outstretched as far as they will go. In this orientation, the skater can be modeled as a cylindrical torso (40 kg, 20 cm average diameter, 160 cm tall) plus two rod-like arms (2.5 kg each, 68 cm long) attached to the outside of the torso. The skater then raises her arms straight above her head, where she appears to be a 45 kg, 20-cm-diameter, 200-cm-tall cylinder. What is her new rotation frequency, in revolutions per second?