# physics

posted by .

A disk, with a radius of 0.25 m, is to be rotated like a merry-go-round through 800 rad, starting from rest, gaining angular speed at the constant rate α1 through the first 400 rad and then losing angular speed at the constant rate -α1 until it is again at rest. The magnitude of the centripetal acceleration of any portion of the disk is not to exceed 400 m/s2. (a) What is the least time required for the rotation? (b) What is the corresponding value of α1?

• physics -

210651.035102351

## Similar Questions

1. ### Physics!

A wheel rotates with a constant angular acceleration of 3.50 rad/s2. The angular speed of the wheel is 2.00 rad/s at t = 0. If the radius of the wheel is doubled, Are the following statements affected?
2. ### PHYSICS

A solid disk with a mass of 100kg and a radius of 0.2m, turns clockwise through an angular displacement 10 rad when starting from rest to attain its maximum angular speed, of 1 revolution every 0.5s. What is the angular acceleration …
3. ### Physics

A solid disk with a mass ok 100 kg and radius of 0.2m turns clockwise through an angular displacement 10 rad when starting from rest attain its maximum angular speed of 1 revolution every 0.5s. How much time did it take for the disk …

A solid disk with a mass ok 100 kg and radius of 0.2m turns clockwise through an angular displacement 10 rad when starting from rest attain its maximum angular speed of 1 revolution every 0.5s. How much time did it take for the disk …

A dentist causes the bit of a high-speed drill to accelerate from an angular speed of 1.44 x 104 rad/s to an angular speed of 5.05 x 104 rad/s. In the process, the bit turns through 1.77 x 104 rad. Assuming a constant angular acceleration, …
6. ### physics

A spinning disk of mass 5.0 kg and radius 0.25m is rotating about an axis through its center at 400 rev/min. a.) What is the angular velocity of the disk in rad/s?
7. ### Physics

A spinning disk of mass 5.0 kg and radius 0.25m is rotating about an axis through its center at 400 rev/min. a.) What is the angular velocity of the disk in rad/s?
8. ### Physics

A dentist causes the bit of a high-speed drill to accelerate from an angular speed of 1.20x10^4 rad/s to an angular speed of 3.14x10^4 rad/s. In the process, the bit turns through 1.92x10^4 rad. Assuming a constant angular acceleration, …
9. ### physics

A disk rotates about its central axis starting from rest and accelerates with constant angular acceleration. At one time it is rotating at 7.8 rad/s; 60 radians later, its angular speed is 19 rad/s. Calculate (a) the angular acceleration …
10. ### Physics

A person exerts a tangential force of 34.8 N on the rim of a disk-shaped merry-go-round of radius 2.60 m and mass 152 kg. If the merry-go-round starts at rest, what is its angular speed after the person has rotated it through an angle …

More Similar Questions