Energy Transformations and Forces Concepts

This lecture covers the conservation of energy, focusing on kinetic and potential energy, and the role of conservative and non-conservative forces. It explains the work-energy theorem and provides an example problem involving a baseball player sliding with friction. The lecture also discusses the law of conservation of energy, energy transformation, and efficiency, highlighting that energy can change forms but the total amount remains constant.

What is the primary characteristic of conservative forces?

• They depend on the path taken.

• They do not depend on the path taken.

• They always decrease energy.

• They always increase energy.

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

• Gravitational force

• Elastic force

• Frictional force

• Magnetic force

In a system with friction, what happens to the energy lost due to friction?

• It is converted to sound energy.

• It is converted to potential energy.

• It is destroyed.

• It is converted to thermal energy.

According to the work-energy theorem, what must be considered in systems with non-conservative forces?

• Only initial kinetic energy

• Only final potential energy

• Gravitational force

• Non-conservative work

In the example of the baseball player, what is the formula used to calculate the sliding distance?

• Distance = f / m * v^2

• Distance = m * v^2 / 2f

• Distance = 2f / m * v^2

• Distance = m * v / f

What does the law of conservation of energy state about the total energy in a process?

• It is always zero.

• It remains constant.

• It can decrease.

• It can increase.

Which of the following is NOT a form of energy mentioned in the lecture?

• Chemical energy

• Radiant energy

• Magnetic energy

• Nuclear energy

What is the efficiency of a gas heater as mentioned in the lecture?

• 100%

• 17%

• 98%

• 50%

Why can no machine be 100% efficient?

• Because of energy creation.

• Due to energy gain.

• Due to energy destruction.

• Because of energy loss.

Which energy transformation is involved in photosynthesis?

• Electrical to thermal

• Nuclear to chemical

• Light to chemical

• Chemical to thermal