Energy Quiz #1 Review

Define energy.

Answer explanation

Energy is the capacity to do work or produce change. It exists in various forms, such as kinetic, potential, thermal, and chemical, and is conserved in closed systems, meaning it cannot be created or destroyed.

What are the units of energy?

Answer explanation

The units of energy include joules (J), calories (cal), and kilowatt-hours (kWh). Joules are the standard SI unit, while calories are commonly used in food energy, and kilowatt-hours are used for electrical energy.

Define the law of conservation of energy.

Answer explanation

The law of conservation of energy states that energy cannot be created or destroyed, only transformed from one form to another. The total energy in a closed system remains constant.

What term refers to the amount of useful energy you get from a system?

Answer explanation

The term that refers to the amount of useful energy obtained from a system is 'useful work' or 'useful energy output'. This indicates the energy that can be harnessed for practical purposes.

Energy that is stored or based on place/position is:

(a)  

Answer explanation

Energy that is stored based on position is known as Potential Energy. It represents the energy an object has due to its location in a force field, such as gravitational or elastic fields.

Energy that is in motion or being utilized is:

(a)  

Answer explanation

Energy that is in motion or being utilized is known as Kinetic Energy. This type of energy is associated with the movement of objects, distinguishing it from potential energy, which is stored energy.

Potential energy is greater when there is a greater ____________ and ____________.

(a)  

Answer explanation

Potential energy increases with greater height and mass. Height refers to the vertical position of an object, while mass is the amount of matter it contains. Both factors contribute to the potential energy of an object.

Kinetic energy is greater when there is a greater ____________ and ____________.

(a)  

Answer explanation

Kinetic energy is calculated using the formula KE = 1/2 mv², where m is mass and v is velocity. Therefore, kinetic energy increases with greater mass and greater velocity.

As energy shifts between PE and KE, what happens to the total energy in a system?

Answer explanation

As energy shifts between potential energy (PE) and kinetic energy (KE), the total energy in a closed system remains constant due to the law of conservation of energy.

What is the state of energy (PE or KE) for movement of atoms, molecules, waves and electrons?

Answer explanation

The movement of atoms, molecules, waves, and electrons is associated with kinetic energy (KE), as they are in motion. Potential energy (PE) relates to their position or configuration, not their movement.