Exam 3 Review

Front

What is the principle of conservation of kinetic energy in inelastic collisions?

Back

In inelastic collisions, kinetic energy is not conserved; some kinetic energy is transformed into other forms of energy, such as heat or sound.

Front

What is Newton's 2nd law of motion?

Back

Newton's 2nd law states that the net force acting on an object is equal to the mass of the object multiplied by its acceleration (F_net = m*a). This law is valid only if the mass of the system is constant.

Front

What happens to a student sitting on a frictionless stool when they hold a rotating wheel and rotate it 180 degrees?

Back

The student will rotate clockwise as viewed from the top due to the conservation of angular momentum.

Front

Is momentum conserved in all types of collisions?

Back

Yes, momentum is conserved in all types of collisions studied, including elastic, inelastic, and completely inelastic collisions.

Front

What condition must be met for angular momentum to be conserved?

Back

Angular momentum is conserved if the net external torque acting on a body is zero.

Front

Define kinetic energy. How is it calculated?

Back

Kinetic energy is the energy of an object due to its motion, calculated using the formula KE = 1/2 mv^2, where m is mass and v is velocity.

Front

What is the difference between elastic and inelastic collisions?

Back

In elastic collisions, both momentum and kinetic energy are conserved. In inelastic collisions, momentum is conserved, but kinetic energy is not.

Front

What is the significance of the net external force in Newton's 2nd law?

Back

The net external force determines the acceleration of an object; if the net force is zero, the object will not accelerate.

Front

Explain the concept of angular momentum. How is it calculated?

Back

Angular momentum is the rotational equivalent of linear momentum, calculated as L = Iω, where L is angular momentum, I is the moment of inertia, and ω is the angular velocity.

Front

What is the role of friction in rotational motion?

Back

Friction can provide the necessary torque to change the rotational motion of an object, but in a frictionless scenario, no torque is applied.