Torque & Rotational Motion

Question 1

What is angular velocity?

Answer 1

It’s equal to the change in angular position divided by the change of time

Question 2

Relationship between angular velocity and linear velocity?

Answer 2

v = w*r

Question 3

What is angular velocity equal to with respect to pi and period?

Answer 3

it’s equal to (2pi * r )/period

Question 4

What is angular acceleration equal to and what is relationship with linear acceleration?

Answer 4

Angular acceleration is equal to the change in angular velocity with respect to time

alpha = a * r

Question 5

What is centripetal acceleration equal to with respect to angular velocity?

Answer 5

A_{c} = w * w * r

Question 6

What is center of mass?

Answer 6

It’s a point within a system where the total mass is concentrated, in other words, it’s the point where the object finds itself in rotational equilibrium.

Xcg = (1/M) * (SUM m_{i} x_{i})

Ycg = (1/M) * (SUM m_{i} y_{i})

Question 7

What is the moment of inertia?

Conceptually and its equation

Answer 7

The moment of inertia represents the resistance of the body to change is angular velocity.

This is the equivalent concept of mass but in rotational kinematics.

I = SUM ( m_{i} * r_{i}^2)

Question 8

What is torque?

Equations for finding its magnitude.

Answer 8

It is the equivalent to force in linear dynamics.

Torque = I * alpha

Torque = Delta L (Change in angular momentum)

Question 9

When the object is not a regular shape, how do you get moment of inertia?

Answer 9

By using an integral:

I = Integral ( dm_{i} * r_{i} ^2 )