Conservation of Energy Part 5: Mechanical Energy and Conservative and non Conservative forces

The video tutorial revisits previous concepts and introduces new ones, such as work done by conservative and non-conservative forces, and mechanical energy. It explains the relationship between work and kinetic energy, and how work done by gravity and springs are examples of conservative forces. Non-conservative forces like friction are also discussed. The video ties these concepts together by showing how total work is the sum of work done by both conservative and non-conservative forces. It concludes with the principle of mechanical energy conservation, emphasizing that mechanical energy remains constant if non-conservative forces do no work.

What is the relationship between total work done and kinetic energy?

• Total work done is equal to the change in kinetic energy.

• Total work done is equal to the sum of kinetic and potential energy.

• Total work done is equal to the change in potential energy.

• Total work done is independent of kinetic energy.

Which of the following is an example of a conservative force?

• Air resistance

• Gravity

• Friction

• Tension

What is a key characteristic of work done by conservative forces?

• It depends only on the initial and final positions.

• It is always positive.

• It is always zero.

• It depends on the path taken.

Which force is considered non-conservative?

• Magnetic force

• Spring force

• Gravity

• Friction

How does work done by non-conservative forces differ from conservative forces?

• It is always zero.

• It results in no net work done.

• It depends on the path taken.

• It depends only on the initial and final positions.

What is the total work done on an object?

• The sum of work done by conservative forces only.

• The difference between work done by conservative and non-conservative forces.

• The sum of work done by both conservative and non-conservative forces.

• The sum of work done by non-conservative forces only.

What does the change in mechanical energy equal?

• The work done by conservative forces.

• The work done by non-conservative forces.

• The sum of kinetic and potential energy.

• The change in potential energy only.

Under what condition is mechanical energy conserved?

• When non-conservative forces do no work.

• When conservative forces do no work.

• When only potential energy changes.

• When non-conservative forces do work.

What happens to mechanical energy in a frictionless pendulum?

• It decreases over time.

• It increases over time.

• It remains constant.

• It becomes zero.

What does the conservation of mechanical energy imply?

• Energy is created within the system.

• Energy remains constant within the system.

• Energy is transferred to the environment.

• Energy is lost in the system.