# Physics

A flywheel turns through 60 rev as it slows from an angular speed of 2.8 rad/s to a stop.
How much time is required for it to complete the first 30 of the 60 revolutions?

1. 👍 0
2. 👎 1
3. 👁 397
1. ave speed = 1.4 rad/s

stop time = 2 * π * 60 / 1.4

acceleration = 2.8 rad/s / stop time
... negative ... wheel is stopping

30 * 2 * π = 1/2 a t^2 + 2.8 t
... solve for t

1. 👍 0
2. 👎 1
2. sdgsd

1. 👍 0
2. 👎 0
3. blaaaaaaaaaaaaaaaaaaaaaaahhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh

1. 👍 0
2. 👎 0

## Similar Questions

1. ### physics

A 4.50-kg wheel that is 34.5 cm in diameter rotates through an angle of 13.8 rad as it slows down uniformly from 22.0 rad/s to 13.5 rad/s. What is the magnitude of the angular acceleration of the wheel? A) 0.616 rad/s 2 B) 22.5

2. ### Physics

A passenger bus in Zurich, Switzerland derived its motive power from the energy stored in a large flywheel. The wheel was brought up to speed periodically, when the bus stopped at a station, by an electric motor, which could then

3. ### trigonometry

A Wheel of radius 14in. is rotating 0.5 rad/sec. What is the linear speed v, the angular speed in RPM ( rev per min), and the angular speed in deg/sec?

4. ### physics

a remote controlled car's wheel accelerates at 22.4 rad/s^2. if the wheel begins with an angular speed of 10.8 rad/s what is the wheel's angular speed after exactly 3 full turns?

1. ### Math

Find the rotation in revolutions per minute given the angular speed and the radius given the linear speed and the rate of rotation. 1. w= 2.7 rad/s 2. v=24.8 m/s, 120 rev/min 3. w= 4/3Pi rad/hr Please help me with these problems!

2. ### physics

As a result of friction, the angular speed of a wheel changes with time according to d(theta)/dt = w0 e^-(aplpha*t) where w0 and alpha are constants. The angular speed changes from an initial angular speed of 4.87 rad/s to 4.27

3. ### physic

hi,need help please.thank. A car is designed to get its energy from a rotating flywheel (solid disk) with a radius of 2.00 m and a mass of 525 kg. Before a trip, the flywheel is attached to an electric motor, which brings the

4. ### physics

What is the angular speed in rev/min of the Earth as it orbits around the sun? I'm confused with this problem. I know we have to convert from rad/s to rev/rad to s/min in order to get the units as rev/min. But I don't know what to

1. ### physics

A car is designed to get its energy from a rotating flywheel (solid disk) with a radius of 1.00 m and a mass of 600 kg. Before a trip, the flywheel is attached to an electric motor, which brings the flywheel's rotational speed up

2. ### Physics (torque, if possible)

An electric motor turns a flywheel through a drive belt that joins a pulley on the motor and a pulley that is rigidly attached to the flywheel. The flywheel is a solid disk with a mass of 80.0kg and a dimaeter of 1.25m. It turns

3. ### Physic

A flywheel rotates with an angular speed of 26 rev/s. As it is brought to rest with a constant acceleration, it turns 55 rev. What is the magnitude of the angular acceleration? How much time does it take to stop?

4. ### physics

A wheel initially rotating at an angular speed of 1.2 rad/s turns through 34 revolutions during the time that it is subject to angular accelaration of .4 rad/s/s. How long did the accelaration last? So I used theta=Wot+.5at^2.