If the moment of inertia of a body is 10 kg m², what is the rotational kinetic e
Practice Questions
Q1
If the moment of inertia of a body is 10 kg m², what is the rotational kinetic energy when it rotates with an angular velocity of 5 rad/s?
125 J
50 J
100 J
75 J
Questions & Step-by-Step Solutions
If the moment of inertia of a body is 10 kg m², what is the rotational kinetic energy when it rotates with an angular velocity of 5 rad/s?
Step 1: Identify the formula for rotational kinetic energy, which is KE = 1/2 I ω².
Step 2: Substitute the given moment of inertia (I = 10 kg m²) into the formula.
Step 3: Substitute the given angular velocity (ω = 5 rad/s) into the formula.
Step 4: Calculate ω², which is 5² = 25.
Step 5: Multiply I (10 kg m²) by ω² (25) to get 10 * 25 = 250.
Step 6: Multiply the result by 1/2 to find KE: 1/2 * 250 = 125 J.
Rotational Kinetic Energy – The energy possessed by a rotating object, calculated using the formula KE = 1/2 I ω², where I is the moment of inertia and ω is the angular velocity.
Moment of Inertia – A measure of an object's resistance to changes in its rotation, dependent on the mass distribution relative to the axis of rotation.
Angular Velocity – The rate of rotation of an object, measured in radians per second.
