Question

In: Physics

A uniform disk with mass m = 9.07 kg and radius R = 1.36 m lies...

A uniform disk with mass m = 9.07 kg and radius R = 1.36 m lies in the x-y plane and centered at the origin. Three forces act in the +y-direction on the disk: 1) a force 313 N at the edge of the disk on the +x-axis, 2) a force 313 N at the edge of the disk on the –y-axis, and 3) a force 313 N acts at the edge of the disk at an angle θ = 31° above the –x-axis.

1)

What is the magnitude of the torque on the disk about the z axis due to F1?

N-m

2)

What is the magnitude of the torque on the disk about the z axis due to F2?

N-m

3)

What is the magnitude of the torque on the disk about the z axis due to F3?

N-m

4)

What is the x-component of the net torque about the z axis on the disk?

N-m

5)

What is the y-component of the net torque about the z axis on the disk?

N-m

6)

What is the z-component of the net torque about the z axis on the disk?

N-m

7)

What is the magnitude of the angular acceleration about the z axis of the disk?

rad/s2

8)

If the disk starts from rest, what is the rotational energy of the disk after the forces have been applied for t = 1.8 s?

J

Solutions

Expert Solution

2) If the line of action of force passes through a point/axis then its torque about that point/axis is zero.

4) same reason as part 2)

5) if a force doesn't have a tendency of rotation about an axis then its torque about that axis is zero.


Related Solutions

A uniform disk with mass m = 9.28 kg and radius R = 1.42 m lies...
A uniform disk with mass m = 9.28 kg and radius R = 1.42 m lies in the x-y plane and centered at the origin. Three forces act in the +y-direction on the disk: 1) a force 345 N at the edge of the disk on the +x-axis, 2) a force 345 N at the edge of the disk on the –y-axis, and 3) a force 345 N acts at the edge of the disk at an angle θ =...
A uniform disk with mass m = 9.44 kg and radius R = 1.32 m lies...
A uniform disk with mass m = 9.44 kg and radius R = 1.32 m lies in the x-y plane and centered at the origin. Three forces act in the +y-direction on the disk: 1) a force 318 N at the edge of the disk on the +x-axis, 2) a force 318 N at the edge of the disk on the –y-axis, and 3) a force 318 N acts at the edge of the disk at an angle θ =...
1. A uniform disk of mass M = 5.00 kg and radius r = 24.0 cm...
1. A uniform disk of mass M = 5.00 kg and radius r = 24.0 cm is mounted on a motor through its center. The motor accelerates the disk uniformly from rest by exerting a constant torque of 1.50 N · m. (a) What is the time required for the disk to reach an angular speed of 8.50 ✕ 102 rpm? (b) What is the number of revolutions through which the disk spins before reaching this angular speed? 2. A...
Consider a thin uniform disk of mass M and radius R. A mass m is located...
Consider a thin uniform disk of mass M and radius R. A mass m is located along the axis of the disk at a distance z from the center of the disk. The gravitational force on the mass m (in terms of m, M, R, G, and z) is
A certain wheel is a uniform disk of radius R = 0.5 m and mass M...
A certain wheel is a uniform disk of radius R = 0.5 m and mass M = 10.0 kg. A constant force of Fapp = 15.0 N is applied to the center of mass of the wheel in the positive x-direction. The wheel rolls along the ground without slipping. (a) Compute the rotational inertia of the wheel about its center of mass. (b) Compute the magnitude and direction of the friction force acting on the wheel from the ground. (c)...
A disk with mass m = 11.8 kg and radius R = 0.31 m begins at...
A disk with mass m = 11.8 kg and radius R = 0.31 m begins at rest and accelerates uniformly for t = 17.2 s, to a final angular speed of ω = 31 rad/s. 1.What is the angular acceleration of the disk? 2. What is the angular displacement over the 17.2 s? 3. What is the moment of inertia of the disk? 4. What is the change in rotational energy of the disk?
A cockroach of mass m lies on the rim of a uniform disk of mass 4.00...
A cockroach of mass m lies on the rim of a uniform disk of mass 4.00 m that can rotate freely about its center like a merry-go-round. Initially the cockroach and disk rotate together with an angular velocity of 0.230 rad/s. Then the cockroach walks half way to the center of the disk. What then is the angular velocity of the cockroach-disk system? What is the ratio K/K0 of the new kinetic energy of the system to its initial kinetic...
A space station in the shape of a uniform disk (mass 4.45x105 kg, radius 262 m)...
A space station in the shape of a uniform disk (mass 4.45x105 kg, radius 262 m) rotates with period 86.1 seconds. There are also 734 astronauts (whom you can treat as point particles) working inside the space station, each of mass 155 kg, and all standing on the outside rim and rotating with the station. Now, all the astronauts move to a conference room at the very center of the space station. Find the new period of the rotation of...
A space station in the shape of a uniform disk (mass 8.44x105 kg, radius 687 m)...
A space station in the shape of a uniform disk (mass 8.44x105 kg, radius 687 m) rotates with period 86.3 seconds. There are also 781 astronauts (whom you can treat as point particles) working inside the space station, each of mass 188 kg, and all standing on the outside rim and rotating with the station. Now, all the astronauts move to a conference room at the very center of the space station. Find the new period of the rotation of...
A uniform disk of mass 371 kg and radius 0.19 m is mounted on frictionless bearings...
A uniform disk of mass 371 kg and radius 0.19 m is mounted on frictionless bearings so it can rotate freely around a vertical axis through its center (see the following figure). A cord is wrapped around the rim of the disk and pulled with a force of 10 N. What is the angular velocity (in rad/s) at the instant the disk has completed four revolutions. The disk starts from rest. Group of answer choices 3.78 rad/s 3.87 rad/s 2.35...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT