3. An ice skater can increase their angular velocity during a spin by pulling their arms...
3. An ice skater can increase their angular velocity during a spin by pulling their arms inward, lowering their moment of inertia. The only external torques are small forces at small radii (in particular, friction in the tip of their skate), and can be ignored. Suppose they begin with their arms fully extended and bring them fully in, reducing their moment of inertia by half.
(a) By what factor will their angular velocity ω change? Explain.
(b) By what factor will their rotational kinetic energy Krot = 1 2 Iω2 change? If it changes, where did the energy come from/go to?
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3. An ice skater can increase their angular velocity during a
spin by pulling their arms...
An ice skater is spinning at a particular rotational velocity when she decides to bring her...
An ice skater is spinning at a particular rotational velocity when she decides to bring her arms inward, thus reducing her moment of inertia. If she reduces her moment of inertia by 20.0%, her rotational velocity will increase by what percent?
As an ice skater begins a spin, his angular speed is 3.37 rad/s. After pulling in...
As an ice skater begins a spin, his angular speed is 3.37 rad/s. After pulling in his arms, his angular speed increases to 5.74 rad/s. A)Find the ratio of the skater's final moment of inertia to his initial moment of inertia.
Problem 2: An ice-skater, as we mentioned in lecture, in order to increase her angular velocity...
Problem 2: An ice-skater, as we mentioned in lecture, in order to increase her angular velocity from 2.0 rev per 1.3 sec to 3.5 rev per sec she needs to decrease her moment of inertia to a value of 4.6 kg m/sec by pulling hers arms towards her body. a) Find her initial moment of inertia when her arms are out-stretched. b) Calculate the rotational kinetic energy for each case.
3. An ice skater starts spinning at a rate of 2.0 rev/s with their arms extended....
3. An ice skater starts spinning at a rate of 2.0 rev/s with their arms extended. They then pull their arms in toward their body reducing their moment of inertia by ¼, what is the angular velocity of the skater with their arms pulled in?
The 160 lb ice skater with arms extended horizontally spins about a vertical axis with a...
The 160 lb ice skater with arms extended horizontally spins about a vertical axis with a rotational speed of 1 rev/sec. Estimate his rotational speed if he fully retracts his arms, bringing his hands very close to the centerline of his body. As a reasonable approximation, model the extended arms as uniform slender rods, each of which is 27 in. long and weighs 13 lb. Model the torso as a solid 134-lb cylinder 13 in. in diameter. Treat the man...
An ice- skater is initially spinning at an angular speed ω = 1.35 revolutions/s with a...
An ice- skater is initially spinning at an angular speed ω = 1.35 revolutions/s with a rotational inertia Ii = 2.30 kg.m2 with her arms extended. When she pulls her arms in, her rotational inertia is reduced to If=1.05 kg.m2 . Assume no external torques act. a) Determine her initial angular speed in rad/s. (1 marks) b) Calculate her final angular speed in RPM (4 marks) c) Calculate the period of rotation when she is at her final speed (1...
An ice skater spins, with her arms and one leg outstretched, and achieves an angular velocity...
An ice skater spins, with her arms and one leg outstretched, and achieves an angular velocity of 2 rad/s. when she pulls in her arms, her moment of inertia decreases to 65% its original value. what is her new angular velocity?
An ice skater spinning with outstretched arms has an angular speed of 5.0rad/s . She tucks...
An ice skater spinning with outstretched arms has an angular speed of 5.0rad/s . She tucks in her arms, decreasing her moment of inertia by 29% . What is the resulting angular speed? rad/s By what factor does the skater's kinetic energy change? (Neglect any frictional effects.) where does the extra kinetic energy come from?
A person spins with their arms extended at an angular velocity of 4 radians/second. When they...
A person spins with their arms extended at an angular velocity of 4 radians/second. When they bring their arms in, their angular velocity becomes 9 radians/second. Their moment of inertia with arms extended was I. What is the skater's moment of inertia with her arms drawn in?
To increase the effect of rotation, figure skaters pull their arms in when they spin Consider...
To increase the effect of rotation, figure skaters pull their arms in when they spin Consider a figure skater with moment of inertia with her arms outstretched of I_i = 3.6kgm^2, and I_f = 1.1kgm^2 with her arms pulled in. She starts out spinning at omega_i = 0.85_s^-1 with her arms outstretched. Find omega_f. the skater's rotational velocity after she pulls her arms in. Find the increase in her rotational kinetic energy. Where does this extra energy come from? Problem...
Problem 2: An ice-skater, as we mentioned in lecture, in order to increase her angular velocity from 2.0 rev per 1.3 sec to 3.5 rev per sec she needs to decrease her moment of inertia to a value of 4.6 kg m/sec by pulling hers arms towards her body. a) Find her initial moment of inertia when her arms are out-stretched. b) Calculate the rotational kinetic energy for each case.
3. An ice skater starts spinning at a rate of 2.0 rev/s with their arms extended. They then pull their arms in toward their body reducing their moment of inertia by ¼, what is the angular velocity of the skater with their arms pulled in?
To increase the effect of rotation, figure skaters pull their arms in when they spin Consider a figure skater with moment of inertia with her arms outstretched of I_i = 3.6kgm^2, and I_f = 1.1kgm^2 with her arms pulled in. She starts out spinning at omega_i = 0.85_s^-1 with her arms outstretched. Find omega_f. the skater's rotational velocity after she pulls her arms in. Find the increase in her rotational kinetic energy. Where does this extra energy come from? Problem...
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