Actually, it's very easy.Aarron Anderson said:Homework Statement
How much torque is needed to change the speed of spinning rate of a 3.50 kg sphere with a radius of 7.50 m from 900. rpm to 200. rpm in 3.0 s? [-1924 -1.92 x 103 Nm]
Homework Equations
t = I * α
I = (2/5)mr^2
t = F * r
The Attempt at a Solution
just can't get a crack at it.[/B]
Angular momentum is a measure of the amount of rotational motion an object has. It is calculated by multiplying the object's moment of inertia by its angular velocity.
Conservation of angular momentum states that the total angular momentum in a system remains constant as long as there are no external torques acting on the system. This means that angular momentum can neither be created nor destroyed, but can only be transferred from one object to another.
Angular momentum and rotational motion are closely related. The direction of an object's angular momentum is perpendicular to its rotational motion and is determined by the right-hand rule. When an object rotates, its angular momentum can change due to external torques.
Yes, angular momentum can be conserved in an isolated system as long as there are no external torques acting on the system. This is known as the law of conservation of angular momentum and is often observed in systems such as planets orbiting around a star.
If the moment of inertia of an object changes, its angular momentum will also change. For example, if an ice skater brings their arms closer to their body, their moment of inertia decreases, causing their angular velocity to increase. This is due to the conservation of angular momentum. Similarly, if the angular velocity of an object changes, its moment of inertia will also change to maintain constant angular momentum.