Energy Conversion and Conservation

Flashcards on Energy Conversion and Conservation

What is the Principle of Conservation of Energy?

Energy cannot be created or destroyed, it can only change forms.

When a falling object is in a vacuum, what energy transfer occurs?

Gravitational potential energy transforms into kinetic energy.

What energy transfers occur in a battery connected to a bulb?

Chemical energy transforms into electrical energy, then into light energy.

What energy transfer occurs in a horizontal mass on a spring?

Elastic potential energy transforms into kinetic energy.

What is kinetic energy?

Energy of a moving object.

What is gravitational potential energy?

Energy gained when an object is lifted and lost when it falls.

What is elastic potential energy?

Energy of a stretched spring or elastic band.

What is chemical energy?

Energy contained in a chemical substance.

What is nuclear energy?

Energy contained within the nucleus of an atom.

What is internal heat energy?

Energy due to temperature or state (thermal energy).

What is dissipation in the context of energy transfers?

Ways in which energy is wasted.

What forms does wasted energy commonly take?

Thermal (heat), light, or sound energy.

In a television, what energy forms are useful and which are wasted?

Light and sound energy are useful, thermal energy is wasted.

In a heater, what energy form is useful and which is wasted?

Thermal energy is useful, sound energy is wasted.

When is work done?

When an object is moved over a distance by an external force applied in the direction of its displacement.

In the diagram of a man pushing a block, what is the man's pushing force doing?

Transferring energy to the block, increasing its kinetic energy.

What can work done be thought of as?

The amount of energy transferred.

If a force acts in the direction that an object is moving, what will happen to the object's energy?

The object will gain energy.

If a force acts in the opposite direction to the movement of an object, what will happen to the object's energy?

The object will lose energy.

How does a gas do work on its surroundings when it expands?

When a gas expands, it exerts pressure on the walls of its container.

What is the efficiency of a system?

The ratio of useful energy output to total energy input.

What does it mean if a system has high efficiency?

Most of the energy transferred is useful.

What does it mean if a system has low efficiency?

Most of the energy transferred is wasted.

What is kinetic energy?

Energy an object has due to its motion or velocity.

When an object is falling, what type of energy is it gaining?

The object is gaining kinetic energy as it gains speed.

What is gravitational potential energy?

Energy stored in an object held at a height above the Earth's surface.

What is elastic potential energy?

Energy stored in objects when they are stretched or compressed.

What is gravitational potential energy associated with?

It is associated with the interaction between bodies due to their masses.

What is elastic potential energy possessed by?

It is possessed by an object due to its state of deformation.

In a uniform field, what force does a body experience?

Experiences the same force (F) at all points.

What is gravitational potential energy?

Energy stored in a mass due to its position in a gravitational field.

If a mass is lifted up, what will happen to its GPE?

It will gain GPE, converted from other forms of energy.

If a mass falls, what will happen to its GPE?

It will lose GPE, and be converted to other forms of energy.

What is taken to be equal to 0?

The potential energy on the Earth's surface at ground level.

What is the power of a machine?

The rate at which it transfers energy.

How else can Power be defined?

The rate of doing work or the work done per unit time.