2. The rotational inertia of a disk about its axis is 0.70 kg m². When a 2.0 kg weight is added to its rim, 0.40 m from the axis, what is the new rotational inertia of the system? 3. A certain wheel has a rotational inertia of 12 kg m². As it turns through 5.0 rev its angular velocity increases from 5.0 rad/s to 6.0 rad/s. Calculate the net torque on the wheel.

2. The rotational inertia of a disk about its axis is 0.70 kg m². When a 2.0 kg weight is added to its rim, 0.40 m from the axis, what is the new rotational inertia of the system? 3. A certain wheel has a rotational inertia of 12 kg m². As it turns through 5.0 rev its angular velocity increases from 5.0 rad/s to 6.0 rad/s. Calculate the net torque on the wheel.

College Physics

1st Edition

ISBN:9781938168000

Author:Paul Peter Urone, Roger Hinrichs

Publisher:Paul Peter Urone, Roger Hinrichs

Chapter10: Rotational Motion And Angular Momentum

Section: Chapter Questions

Problem 34PE: In softball, the pitcher throws with the arm fully extended (straight at the elbow). In a fast pitch...

See similar textbooks

Similar questions

A bar on a hinge starts from rest and rotates with an angular acceleration = 10 + 6t, where is in rad/s2 and t is in seconds. Determine the angle in radians through which the bar turns in the first 4.00 s.
A large grinding wheel in the shape of a solid cylinder of radius 0.330 m is free to rotate on a friction less, vertical axle. A constant tangential force of 250. N applied to its edge causes the wheel to have an angular acceleration of 0.940 rad/s2. (a) What is the moment of inertia of the wheel? (b) What is the mass of the wheel? (c) If the wheel starts from rest, what is its angular velocity after 5.00 s have elapsed, assuming the force is acting during that time?
A large grinding wheel in the shape of a solid cylinder of radius 0.330 m is free to rotate on a friction less, vertical axle. A constant tangential force of 250. N applied to its edge causes the wheel to have an angular acceleration of 0.940 rad/s2. (a) What is the moment of inertia of the wheel? (b) What is the mass of the wheel? (c) If the wheel starts from rest, what is its angular velocity after 5.00 s have elapsed, assuming the force is acting during that time?
A grinding wheel is in the form of a uniform solid disk of radius 7.00 cm and mass 2.00 kg. It starts from rest and accelerates uniformly under the action of the constant torque of 0.600 N m that the motor exerts on the wheel. (a) How long does the wheel take to reach its final operating speed of 1 200 rev/min? (b) Through how many revolutions does it turn while accelerating?
A soccer player extends her lower leg in a kicking motion by exerting a force with the muscle above the knee in the front of her leg. She produces an angular acceleration of 30.00 rad/s2 and her lower leg has a moment of inertia of 0.750kg-m2 What is the force exerted by the muscle if its effective perpendicular lever arm is 1.90 cm?
A potters wheel moves uniformly from rest to an angular speed of 1.00 rev/s in 30.0 s. (a) Find its average angular acceleration in radians per second per second. (b) Would doubling the angular acceleration during the given period have doubled the final angular speed?
A basketball player entertains the crowd by spinning a basketball on his nose. The basketball has a mass of 0.600 kg and a radius of 0.121 m. If the basketball is spinning at a rate of 3.00 revolutions per second, (a) what is its rotational kinetic energy? (See Section 8.6.) (b) What is the magnitude of its angular momentum? Treat the ball as a thin, spherical shell. (See Section 8.7.)
Suppose a child gets off a rotating merry-go-round, Does the angular velocity of the merry-go-round increase, decrease, or remain the same if: (a) He jumps off radially? (b) He Jumps backward to land motionless? (c) He jumps straight up and hangs onto an overhead tree branch? (d) He jumps off forward, tangential to the edge? Explain your answers. (Refer to Figure 10.34).
The angular speed of a wheel is given by (t) = 72.5 rad/s + (9.34 rad /s2) t. a. Is the wheels angular acceleration constant? Explain. b. Find an expression for the angular acceleration.
A bus contains a 1500 kg flywheel (a disk that has a 0.600 m radius) and has a total mass of 10,000 kg. (a) Calculate the angular velocity the flywheel must have to contain enough energy to take the bus from rest to a speed of 20.0 m/s, assuming 90.0% of the rotational kinetic energy can be transformed into translational energy. (b) How high a hill can the bus climb with this stored energy and still have a speed of 3.00 m/s at the top of the hill? Explicitly show how you follow the steps in the Problem-Solving Strategy for Rotational Energy.
Four objectsa hoop, a solid cylinder, a solid sphere, and a thin, spherical shelleach have a mass of 4.80 kg and a radius of 0.230 m. (a) Find the moment of inertia for each object as it rotates about the axes shown in Table 8.1. (b) Suppose each object is rolled down a ramp. Rank the translational speed of each object from highest to lowest, (c) Rank the objects rotational kinetic energies from highest to lowest as the objects roll down the ramp.
In softball, the pitcher throws with the arm fully extended (straight at the elbow). In a fast pitch the ball leaves the hand with a speed of 139 km/h. (a) Find the rotational kinetic energy of the pitcher's arm given its moment of inertia is 0.720kg-m2 and the ball leaves the hand at a distance of 0.600 m from the pivot at the shoulder. (b) What force did the muscles exert to cause the arm to rotate if their effective perpendicular lever arm is 4.00 cm and the ball is 0.156 kg?