Energy

Which of the following is an energy store?

• Waves

• Electrical Current

• Thermal

• Heating

Answer explanation

Thermal energy is stored in the form of heat, making it an energy store. Waves and electrical current are forms of energy transfer, while heating refers to the process of transferring thermal energy, not a store.

Which of the following statements about a closed system is correct?

• energy is only transferred out of the system

• the total energy is always the same before and after an energy transfer

• there is no transfer of energy within the system

• some of the energy is dissipated from the system

Answer explanation

In a closed system, energy is conserved, meaning the total energy remains constant before and after any transfer. This aligns with the principle of conservation of energy, making the correct statement: the total energy is always the same.

What is a gravitational energy store?

• The potential energy an object possesses due to its position above the earth.

• Energy an object has because it is moving

• Energy stored by an object because it has been stretched or squashed

• Energy stored because an object is warm. A form of kinetic energy caused due to the motion of particles.

Answer explanation

A gravitational energy store refers to the potential energy an object has due to its height above the Earth. This energy is related to the object's position in a gravitational field, making the first choice correct.

What is a kinetic energy store?

• The potential energy an object possesses due to its position above the earth.

• Energy an object has because it is moving

• Energy stored by an object because it has been stretched or squashed

• Energy stored because an object is warm. A form of kinetic energy caused due to the motion of particles.

Answer explanation

A kinetic energy store refers to the energy an object has because it is moving. This distinguishes it from potential energy, which is related to an object's position, and other forms of energy like thermal or elastic energy.

What is an elastic energy store?

• The potential energy an object possesses due to its position above the earth.

• Energy an object has because it is moving

• Energy stored by an object because it has been stretched or squashed

• Energy stored because an object is warm. A form of kinetic energy caused due to the motion of particles.

Answer explanation

An elastic energy store refers to the energy stored in an object when it is stretched or squashed, such as in springs or rubber bands. This is distinct from potential energy due to height or kinetic energy from motion.

What is a thermal energy store?

• The potential energy an object possesses due to its position above the earth.

• Energy an object has because it is moving

• Energy stored by an object because it has been stretched or squashed

• Energy stored because an object is warm. A form of kinetic energy caused due to the motion of particles.

Answer explanation

A thermal energy store refers to energy stored in an object due to its temperature. This energy is a form of kinetic energy resulting from the motion of particles, making the correct choice about warm objects.

What is a nuclear energy store?

• The energy stored in chemical bonds

• The energy stored when repelling charges have been moved closer together or when attracting charges have been pulled further apart.

• The energy stored in the nucleus of an atom

Answer explanation

A nuclear energy store refers to the energy stored in the nucleus of an atom. This energy is released during nuclear reactions, distinguishing it from other forms of energy like chemical or electrostatic energy.

What is a chemical energy store?

• The energy stored in chemical bonds

• The energy stored when repelling charges have been moved closer together or when attracting charges have been pulled further apart.

• The energy stored in the nucleus of an atom

Answer explanation

A chemical energy store refers to the energy stored in chemical bonds. This energy can be released during chemical reactions, making it essential for processes like combustion and metabolism.

What is an electromagnetic energy store?

• The energy stored in chemical bonds

• The energy stored when repelling charges have been moved closer together or when attracting charges have been pulled further apart.

• The energy stored in the nucleus of an atom

Answer explanation

An electromagnetic energy store refers to the energy associated with the position of charges. It is specifically the energy stored when repelling charges are brought closer or attracting charges are pulled apart.

What is the unit for energy?

• Watts

• Joules

• Seconds

• Minutes

Answer explanation

The unit for energy is Joules, which measures the amount of work done or energy transferred. Watts measure power, while seconds and minutes are units of time, not energy.