All Flashcards
Define angular momentum.
The rotational version of linear momentum; a measure of an object's 'rotational motion'.
Define moment of inertia ().
A measure of an object's resistance to rotational acceleration about a specific axis.
Define angular velocity ().
The rate of change of angular displacement; how fast an object is rotating.
Define torque.
A twisting force that tends to cause rotation.
State the formula for angular momentum ().
, where is the moment of inertia and is the angular velocity.
What are the steps to solve a conservation of angular momentum problem?
- Identify the initial and final states. 2. Determine if any external torques are acting on the system. 3. If no external torques, set initial angular momentum equal to final angular momentum (). 4. Substitute appropriate formulas for angular momentum (e.g., ). 5. Solve for the unknown variable.
What is the effect of a skater pulling their arms inward during a spin?
The skater's moment of inertia decreases, causing their angular velocity to increase to conserve angular momentum.
What is the effect of applying an external torque to a rotating object?
The object's angular momentum will change.
What happens to the rod's angular speed if the disk bounces back in the disk and rod collision?
The rod's angular speed will be greater because the disk transfers more angular momentum to the rod.