How long does it take for the rotational kinetic energy to become half its initial value, so it is 15.0 J? Express your answer to three significant figures and include the appropriate units.

A turn table starts from 10 rad/s of angular velocity and slows down to a stop in 5.0 s. Find the total angle turned during this time, in rad. Hint: use rotational kinematics formula. Assume initial angle and final angular velocity as zero.

An electric grinder is switched on at t = 0, accelerates uniformly for 15 s to its operating angular speed of 22 rad/s. The wheel then turns at constant angular speed for 35 s and is switched off, slowing uniformly at 3.5 rad/s² until it stops. From the time it is switched off, how long does the grinder take to stop turning? t = S Record your numerical answer below, assuming three significant figures. Remember to include a "-" as necessary.

3 significant digits

The uniform solid block in the figure has mass 21.3 kg and edge lengths a=0.754 m, b = 1.33 m, and c = 0.0662 m. Calculate its rotational inertia about an axis through one corner and perpendicular to the large faces. Number Mo Units Rotation axis

Hi please help: a solid disk of radius R= 70 cm rotates about its center at an angular speed of 43 revolutions per minute. The mass of the disk is M= 7.7 kg. The moment of inertia of a solid disk is given by 1/2 MR^2. What is the rotational kinetic energy (in Joules) of the disk? Answer with three significant figures

Two wheels A and B in the figure are connected by a belt that does not slip. The radius of B is 2.10 times the radius of A. What would be the ratio of the rotational inertias IA/lB if the two wheels had (a) the same angular momentum and (b) the same rotational kinetic energy? (a) Number Units (b) Number i Units

A flywheel is a solid disk that rotates about an axis that is perpendicular to the disk at its center. Rotating flywheels provide a means for storing energy in the form of rotational kinetic energy and are being considered as a possible alternative to batteries in electric cars. The gasoline burned in a 144-mile trip in a typical midsize car produces about 1.05 x 109 J of energy. How fast would a 18.7-kg flywheel with a radius of 0.247 m have to rotate to store this much energy? Give your answer in rev/min.

A 5kg sphere with a radius of 10 cm is spinning at an angular of 15rads/s. What is the rotational kinetic energy (in j) of the solid sphere? The final answer in 2 decimal places

A 100 g disk with a diameter of 10 cm rotates about an axis through its center of mass with 0.2 J of rotational kinetic energy. What is the speed of a point on the rim of the disk?