Rotational Kinematics (use rotational kinematic equations) 2. A centrifuge turning at 20000 rpm is suddenly turned off. Before it comes to a stop, the centrifuge spins for 1500 revolutions. Calculate the angular acceleration of the centrifuge assuming it to be constant. Page 3 of 4 Solution and Answer: We first convert 20000 rpm to rad/s. In doing so we get Wo = 20000 rpm (o seconds) (i revolution/ 1 minute Zn radians 2094.4 d (use this value for the initial angular velocity, wo) 1500 revolutions are equivalent to A8rad = 1500 rev x 2n = 9424.78 radians. (use this value for the angular position, 0) Now, given the initial angular velocity, wo final angular velocity, w and angular position, 0, which of the given rotational kinematic equations are you going to use for computing the angular acceleration, a? Show your solution and answer for the a of the centrifuge.

Rotational Kinematics (use rotational kinematic equations) 2. A centrifuge turning at 20000 rpm is suddenly turned off. Before it comes to a stop, the centrifuge spins for 1500 revolutions. Calculate the angular acceleration of the centrifuge assuming it to be constant. Page 3 of 4 Solution and Answer: We first convert 20000 rpm to rad/s. In doing so we get Wo = 20000 rpm (o seconds) (i revolution/ 1 minute Zn radians 2094.4 d (use this value for the initial angular velocity, wo) 1500 revolutions are equivalent to A8rad = 1500 rev x 2n = 9424.78 radians. (use this value for the angular position, 0) Now, given the initial angular velocity, wo final angular velocity, w and angular position, 0, which of the given rotational kinematic equations are you going to use for computing the angular acceleration, a? Show your solution and answer for the a of the centrifuge.

College Physics

1st Edition

ISBN:9781938168000

Author:Paul Peter Urone, Roger Hinrichs

Publisher:Paul Peter Urone, Roger Hinrichs

Chapter6: Uniform Circular Motion And Gravitation

Section: Chapter Questions

Problem 16PE: Olympic ice skaters are able to spin at about 5 rev/s. (a) What is their angular velocity in radians...

See similar textbooks

Similar questions

Olympic ice skaters are able to spin at about 5 rev/s. (a) What is their angular velocity in radians per second? (b) What is the centripetal acceleration of the skater's nose if it is 0.120 m from the axis of rotation? (c) An exceptional skater named Dick Button was able to spin much faster in the 1950s than anyone since—at about 9 rev/s. What was the centripetal acceleration of the tip of his nose, assuming it is at 0.120 m radius? (d) Comment on the magnitudes of the accelerations found. It is reputed that Button ruptured small blood vessels during his spins.
Integrated Concepts An ultracentrifuge accelerates from rest to 100,000 rpm in 2.00 min. (a) What is its angular acceleration in rad/s2? (b) What is the tangential acceleration of a point 9.50 cm from the axis of rotation? (c) What is the radial acceleration in m/s2 and multiples of g of this point at full rpm?
While punting a football, a kicker rotates his leg about the hip joint. The moment of inertia of the leg is 3.75kgm2 and its rotational kinetic energy is 175 J. (a) What is the angular velocity of the leg? (b) What is the velocity of tip of the punter’s shoe if it is 1.05 m from the hip joint?
Suppose a child walks from the outer edge of a rotating merry-go-round to the inside. Does the angular velocity of the merry-go-round increase, decrease, or remain the same? Explain your answer. Assume the merry-go-round is spinning without friction.
You have a grindstone (a disk) that is 90.0 kg, has a 0.340-m radius, and is turning at 90.0 rpm, and you press a steel axe against it with a radial force of 20.0 N. (a) Assuming the kinetic coefficient of friction between steel and stone is 0.20, calculate the angular acceleration of the grindstine. (b) How many turns will the stone make before coming to rest?
The tub of a washer goes into its spin cycle, starting from rest and gaining angular speed steadily for 8.00 s, at which time it is turning at 5.00 rev/s. At this point, the person doing the laundry opens the lid, and a safety switch turns off the washer. The tub smoothly slows to rest in 12.0 s. Through how many revolutions does the tub turn while it is in motion?
While punting a football, a kicker rotates his leg about the hip joint. The moment of inertia of the leg is 3.75kg-m2 and its rotational kinetic energy is 175 J. (a) What is the angular velocity of the leg? (b) What is the velocity of tip of the punter's shoe if it is 1.05 m from the hip joint? (c) Explain how the football can be given a velocity greater than the tip of the shoe (necessary for a decent kick distance).
The dung beetle is known as one of the strongest animals for its size, often forming balls of dung up to 10 times their own mass and rolling them to locations where they can be buried and stored as food. A typical dung ball formed by the species K. nigroaeneus has a radius of 2.00 cm and is rolled by the beetle at 6.25 cm/s. (a) What is the rolling balls angular speed? (b) How many full rotations are required if the beetle rolls the ball a distance of 1.00 m?
A baseball bat is swung. Do all points on the bat have the same angular velocity? The same tangential speed?
In 2015, in Warsaw, Poland, Olivia Oliver of Nova Scotia broke the world record for being the fastest spinner on ice skates. She achieved a record 342 rev/min, beating the existing Guinness World Record by 34 rotations. If an ice skater extends her aims at that rotation rate, what would be her new rotation rate? Assume she can be approximated by a 45-kg rod that is 1.7 m tall with a radius of 15 cm in the record spin. With her aims stretched take the approximation of a rod of length 130 cm with 10 of her body mass aligned perpendicular to the spin axis. Neglect frictional forces.
There an analogy between rotational and physical quantities. What rotational quantities are analogous to distance and velocity?
(a) What is the angular speed of the second hand of a clock? (b) What is the direction of as you view a clock hanging on a vertical wall? (c) What is the magnitude of the angular acceleration vector of the second hand?