Introductory Rotational Form of Newton's Second Law Problem

The video tutorial explains how to calculate the angular acceleration of a uniform solid disk. It begins with a problem statement involving a disk, a string, and a force. The rotational inertia is calculated, followed by a free body diagram to identify forces and torques. The angular acceleration is then determined using the relationship between torque and rotational inertia. The tutorial concludes with a discussion on the choice of direction for torque and angular acceleration, emphasizing the importance of consistent definitions in physics problems.

What is the force applied to the disk in the problem?

• 20 Newtons

• 11 Newtons

• 15 Newtons

• 9 Newtons

What is the formula for the rotational inertia of a solid disk about its center of mass?

• mass times radius

• 1/2 mass times radius squared

• mass times radius squared

• 1/2 mass times radius

In the free body diagram, which direction is defined as positive torque?

• Into the board

• Counterclockwise

• Out of the board

• Clockwise

What is the net torque on the disk if the force applied is opposite to the positive torque direction?

• Negative of the torque due to force applied

• Zero

• Equal to the torque due to force applied

• Twice the torque due to force applied

Why is the angle between the radius vector and the force applied always 90 degrees?

• Because the disk is stationary

• Because the force is applied at the center

• Because the string is always tangent to the circle

• Because the disk is a square