A.4 Rigid body mechanics HL

Question 1

Moment of Inertia

Answer 1

A measure of an object’s resistance to changes in its rotation. The further the mass from the axis of rotation, the higher it is

Question 2

Axis of Rotation

Answer 2

An imaginary line around which an object rotates. Moment of inertia depends on the mass distribution relative to this axis

Question 3

Rotational Motion

Answer 3

Movement of a body around an axis, where all points in the body move in circles around the axis

Question 4

Conservation of Angular Momentum

Answer 4

Angular momentum of a system remains constant if no external torque is applied

Question 5

Kinetic Energy in Rotational Motion

Answer 5

The energy a body possesses due to its rotation, which is part of its total kinetic energy

Question 6

Angular Acceleration

Answer 6

The rate of change of angular velocity over time. Constant in uniformly angularly accelerated motion

Question 7

Angular Displacement

Answer 7

The change in the angle as an object rotates, measured in radians

Question 8

Angular Velocity

Answer 8

The rate of change of angular displacement, measured in radians per second

Question 9

Suvat Equations for Rotation

Answer 9

Equations that describe uniformly angularly accelerated motion, analogous to linear suvat equations.

Question 10

Rotational Kinetic Energy

Answer 10

Energy due to angular motion, calculated differently from linear kinetic energy

Question 11

Torque

Answer 11

A force’s tendency to cause rotation around an axis. Quantifies the turning effect.

Question 12

Rotational Equilibrium

Answer 12

A state where no net torque acts on a body, resulting in no angular acceleration.

Question 13

Resultant Torque

Answer 13

The net torque from combined forces acting on a body, determining its rotational acceleration

Question 14

Couple

Answer 14

A pair of equal and opposite forces whose effect is to rotate a body without translating it

Question 15

Center of Mass

Answer 15

The point in an object that moves as if all the object’s mass were concentrated at that point

Question 16

Angular Momentum

Answer 16

The quantity of rotation of a body, conserved in the absence of external torques.

Question 17

Conservation of Angular Momentum

Answer 17

Principle stating that the total angular momentum of a system remains constant if no external torque is applied

Question 18

Angular Impulse

Answer 18

Change in angular momentum, equal to the integral of torque over time.

Question 19

Torque-Time Graph

Answer 19

A graph showing torque applied over time; the area under the curve represents angular impulse.

Question 20

Rolling Motion

Answer 20

A combination of translational and rotational motion, where kinetic energy is split between the two types.