What is the initial angular momentum of the object? What is the new angular spee

Question

What is the initial angular momentum of the object? What is the new angular speed if the spokes. are lengthened from 2 m to 6 m? What is the new angular momentum of the object? A merry-go-round rotates at the rate of 0.25 rev/s with an 71 kg man standing at a point 2.2 m from the axis of rotation. What is the new angular speed when the man walks to a point 0 m from the center? Consider the merry-ground is a solid 81 kg cylinder of radius of 2.2 m What is the change in kinetic energy due to this movement? A cylinder with moment of inertia 12.7 kg m^2 rotates with angular velocity 5.71 rad/s on a frictionless vertical axle. A second cylinder, with moment of inertia 25.8 kg m^2, initially not rotating, drops onto the first cylinder and remains in contact. Since the surfaces are rough, the two eventually reach the same angular velocity. Calculate the final angular velocity Show that energy is lost in this situation by calculating the ratio of the final to the initial kinetic energy. A projectile of mass m = 1.24 kg moves to the right with speed v_o = 29.7 m/s. The object projectile strikes and sticks to the end of the stationary rod of mass M = 3.38 kg and length d = 1.92 m that is pivoted about a frictionless axle through its center. How much kinetic energy is lost in the collision relative to the initial kinetic energy? What is the change in kinetic energy.

Explanation / Answer

009) It is an example of conservation of angular momentum

mass of the merry go round M = 81 kg

mass of the man m = 71 kg

initial angular speed w1= 0.25 rev/s = 0.25 x 2 x 3.14 = 1.57 rad/s

Initial moment of inertia of the system I1 = 0.5 M R2  + m r2

=( 0.5 x 81 x 2.2 x 2.2) + ( 71 x2.2 x 2.2)

= 196.02 + 343.64

= 539.66 kg-m2

from law of conservation of angular momentum I1w1 = I2w2

new angular speed w2 =   I1w1/I2  = 539.66 x 1.57/ ( 0.5 x 81 x 2.2 x 2.2)

= 539.66 x 1.57 /196.02

= 4.32 rad/s

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.