6.8A & 6.8B Energy Types, Transfers and Transformations

Kinetic energy is:

• a form of potential energy

• energy due to motion

• energy stored in chemical bonds

• energy that is lost as heat

Answer explanation

Kinetic energy is defined as energy due to motion. It is the energy an object possesses because of its movement, distinguishing it from potential energy, which is stored energy.

Which of the following is an example of gravitational potential energy?

• A moving car

• A book on a shelf

• A spinning wheel

• A compressed spring

Answer explanation

Gravitational potential energy is the energy stored in an object due to its height. A book on a shelf has potential energy because it is elevated above the ground, unlike a moving car, spinning wheel, or compressed spring.

The type of energy stored in the chemical bonds between atoms within a molecule is:

• Kinetic energy

• Thermal energy

• Chemical energy

• Nuclear energy

Answer explanation

The energy stored in the chemical bonds between atoms is known as chemical energy. It is released or absorbed during chemical reactions, distinguishing it from kinetic, thermal, and nuclear energy.

Which type of potential energy is stored in a deformed elastic object?

• Gravitational Potential Energy

• Elastic Potential Energy

• Chemical Potential Energy

• Kinetic Energy

Answer explanation

The potential energy stored in a deformed elastic object, such as a stretched spring or compressed rubber band, is called Elastic Potential Energy. This energy is released when the object returns to its original shape.

The key relationship between potential energy and kinetic energy is:

• Potential energy is always greater than kinetic energy.

• Kinetic energy is always greater than potential energy.

• Potential energy can be converted into kinetic energy and vice versa.

• They are unrelated forms of energy.

Answer explanation

The correct choice is that potential energy can be converted into kinetic energy and vice versa. This relationship is fundamental in physics, illustrating how energy transforms between these two forms.

The key distinction between potential energy and kinetic energy is:

• Potential energy is energy stored in an object due to its position, while kinetic energy is energy of an object due to its motion.

• Potential energy is energy of an object due to its motion, while kinetic energy is energy stored in an object due to its position.

• Potential energy and kinetic energy are both forms of energy related to temperature.

• Potential energy and kinetic energy are both forms of energy related to chemical reactions.

Answer explanation

The correct choice highlights that potential energy is stored due to an object's position, while kinetic energy is associated with its motion. This distinction is fundamental in understanding energy types.

Which of the following is an example of kinetic energy?

• A) A ball rolling across the floor

• B) A rock at the top of a hill

• C) A compressed spring

• D) Food before it is digested

Answer explanation

Kinetic energy is the energy of motion. A ball rolling across the floor is in motion, thus it possesses kinetic energy. In contrast, a rock at the top of a hill has potential energy, a compressed spring stores elastic potential energy, and undigested food contains chemical energy.

True or False: Elastic potential energy is stored in an object when it is stretched or compressed.

• True

• False

Answer explanation

True. Elastic potential energy is indeed stored in an object when it is stretched or compressed, as seen in springs and rubber bands. This energy is released when the object returns to its original shape.

Gravitational potential energy can be converted into kinetic energy when:

• an object is lifted to a higher position.

• an object is at rest on the ground.

• an object falls from a height.

• an object is pushed on a flat surface.

Answer explanation

Gravitational potential energy is converted into kinetic energy when an object falls from a height. As it descends, the potential energy decreases while the kinetic energy increases, demonstrating energy transformation.

The type of energy stored within chemical bonds of molecules is:

• Kinetic energy

• Thermal energy

• Chemical energy

• Nuclear energy

Answer explanation

The energy stored in chemical bonds is known as chemical energy. It is released or absorbed during chemical reactions, distinguishing it from kinetic, thermal, and nuclear energy.