A person walks into a room and switches on the ceiling fan. Thefan accelerates with constant angular acceleration for 15 s untilit reaches its operating angular speed of 1.9 rotations>s—afterthat its speed remains constant as long as the switch is “on.” Theperson stays in the room for a short time; then, 5.5 minutes afterturning the fan on, she switches it off again and leaves the room.The fan now decelerates with constant angular acceleration, taking 2.4 minutes to come to rest. What is the total number of revolutions made by the fan, from the time it was turned on until thetime it stopped?

The end of the cutting cord on a gas-powered weed cutter is 0.21 m in length. If the motor starts from rest and accelerates with an angular acceleration of 52 rad/s² for 1.82 s then continues with uniform angular velocity. What is the rpm of the cutting cord after the 1.82 s?

A particular DVD player has an operational angular velocity of 2500 rpm. We model thespinning DVD as a disk (I = 0.5 mr^2) with radius r = 0.1m, m = 40 g. A) What is the centripetal acceleration of a point on the edge of the DVD when it is spinningat operational speed? What is the tangential velocity of this point?   B) We turn off the DVD player and notice it takes 3 seconds for the DVD to stop spinningdue to kinetic friction. What is the angular acceleration of the DVD? How many rotations does theDVD make before it stops?   C) If we model the total kinetic friction force acting on the DVD as acting on a point r = 0.05m from the center of the disk, pointing in the direction opposite of the motion at this point, then whatis the coefficient of kinetic friction between the disk and the disk tray?

An ultracentrifuge accelerates at a constant rate from rest to 108500rpm in 2 minutes. All questions refer to the magnitude of the quantities only. What is the angular acceleration in rad/s^2? What is the tangential acceleration of a point 9cm from the axis of rotation? What is the centripetal acceleration of this point at full rpm?

A turntable is off and is not spinning. A 0.9 g ant is on the disc and is 14 cm away from the center. The turntable is turned on and 1.4 s later it has an angular speed of 33 rpm. Assume the angular acceleration is constant and determine the following quantities for the ant 0.7 s after the turntable has been turned on. Express all quantities using appropriate mks units. a => W = V= atan arad a= Fnet

A wheel with a radius of 0.4 meters initially at rest and begins to accelerate at 4 rad/s2. How many revolutions will the wheel travel in 4 seconds?

A young boy swings a yo-yo horizontally above his head so that the yo-yo has a cen- tripetal acceleration of 220 m/s². If the yo-yo's string is 0.26 m long, what is the yo-yo's tangential speed? Answer in units of m/s.

A bicycle wheel is rotating at 40 rpm when the cyclist begins to pedal harder, giving the wheel a constant angular acceleration of 0.50 rad/s^2 What is the wheel's angular velocity, in rpm, 8.0 s later?

A fan blade with a diameter of 1.373 m is rotating at a rate of 3898 revolutions per minute. A piece of gum that is attached to the end of the fan blade suddenly becomes loose while its velocity vecor was momentarily pointing straight up. How long will it take for the piece of gum to come back down? Assume that there is no air resistance.

The tires of a car make 85.0. revolutions as the car reduces its speed uniformly from 90.0 km/hr to 60.0 km/hr. The tires have a diameter of 0.90 m. What is the angular acceleration? If the car continues to slow down at this rate, how much more time is required to stop?