Question

A figure skater is spinning slowly with arms outstretched. He brings his arms in close to...

A figure skater is spinning slowly with arms outstretched. He brings his arms in close to his body and his angular velocity changes by a factor of 2. By what factor does his moment of inertia change, and why?

Homework Answers

Answer #1

(1) when arms are outstretched, the angular speed and moment of inertia are and I respectively. for the 2nd case when arm close to his body the angular speed changed by a factor of two, therefore new angular speed is;

' = 2 and assuming new moment of inertia as I'.

Since, there is no external torque in the system, angular momentum is conserved, so apply conservaton of angular momentum;

moment of inertia changes due to the change in position of arms.

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
The outstretched hands and arms of a figure skater preparing for a spin can be considered...
The outstretched hands and arms of a figure skater preparing for a spin can be considered a slender rod pivoting about an axis through its center (Figure 1). When his hands and arms are brought in and wrapped around his body to execute the spin, the hands and arms can be considered a thin-walled hollow cylinder. His hands and arms have a combined mass 9.0 kg . When outstretched, they span 1.6 m ; when wrapped, they form a cylinder...
The outstretched hands and arms of a figure skater preparing for a spin can be considered...
The outstretched hands and arms of a figure skater preparing for a spin can be considered a slender rod pivoting about an axis through its center (Figure 1). When his hands and arms are brought in and wrapped around his body to execute the spin, the hands and arms can be considered a thin-walled hollow cylinder. His hands and arms have a combined mass 8.0 kg . When outstretched, they span 1.7 m ; when wrapped, they form a thin-walled...
The outstretched hands and arms of a figure skater preparing for a spin can be considered...
The outstretched hands and arms of a figure skater preparing for a spin can be considered a slender rod pivoting about an axis through its center. (See the figure below (Figure 1).) When the skater's hands and arms are brought in and wrapped around his body to execute the spin, the hands and arms can be considered a thin-walled hollow cylinder. His hands and arms have a combined mass of 7.5 kgkg . When outstretched, they span 1.8 mm ;...
What is the angular momentum of a figure skater spinning at 3.2rev/s with arms in close...
What is the angular momentum of a figure skater spinning at 3.2rev/s with arms in close to her body, assuming her to be a uniform cylinder with a height of 1.5m , a radius of 16cm , and a mass of 55kg? How much torque is required to slow her to a stop in 4.4s , assuming she does not move her arms?
a figure skater presses off the ice to begin spinning with her arms close to her...
a figure skater presses off the ice to begin spinning with her arms close to her body. after completing 2 turns in 0.8 seconds she moves her arms further away from her body, what will her new angular velocity be? a. <16.6rad/s b. 18 rad/s c. 20 rad/s d. 24 rad/s
The moment of inertia of an ice skater is 0.400 kg·m2 when he is spinning at...
The moment of inertia of an ice skater is 0.400 kg·m2 when he is spinning at 6.00 rev/s. (a) He reduces his angular velocity by extending his arms and increasing his moment of inertia. Find the value of his moment of inertia if his angular velocity decreases to 1.25 rev/s. (b) Suppose instead he keeps his arms in and allows friction on the ice to slow him to 3.00 rev/s What average torque was exerted if this takes 15.0 s?
A rapidly spinning ice skater has her hands close to her body. She then extends her...
A rapidly spinning ice skater has her hands close to her body. She then extends her arms horizontally. What change, if any, will there be in the following quantities related to her motion? Moment of Inertia, Angular velocity, Angular Momentum. Ignoring friction, tell whether each would increase, decrease, or remain constant.
An ice skater with a moment of inertia of 0.390 kg*m2 is spinning at 6.00 rev/s...
An ice skater with a moment of inertia of 0.390 kg*m2 is spinning at 6.00 rev/s a. What is the angular velocity of the ice skater in rad/s? b. What is the angular momentum of the ice skater at this angular velocity c. He reduces his rate of spin (angular velocity) by extending his arms and increasing his moment of inertia. Find the value of his moment of inertia if his angular velocity drops to 1.70 rev/s d. Suppose instead...
2. An iceskater is turning at a PERIOD of (1/3) second with his arms outstretched. a)...
2. An iceskater is turning at a PERIOD of (1/3) second with his arms outstretched. a) What is his ANGULAR VELOCITY w? b) If he pulls his arms towards his body to reduce his MOMENT OF INTERTIA by 1⁄2, what is his ANGULAR VELOCITY w? c) How much does his ROTATIONAL KINETIC ENERGY change? That is, if the initial Kinetic Energy is (KE)initial, what is the final KE? d) Where did that ENERGY come from, or go to?
What is the angular momentum of a figure skater spinning at 2.3 rev/s with arms in...
What is the angular momentum of a figure skater spinning at 2.3 rev/s with arms in close to her body, assuming her to be a uniform cylinder with a height of 1.5 m, a radius of 16 cm , and a mass of 49 kg ? How much torque(in magnitude) is required to slow her to a stop in 4.8 s , assuming she does not move her arms?