3-3 Work and Energy Quiz

What does the law of conservation of energy state?

• Energy can be created but not destroyed

• Energy can be destroyed but not created

• Energy cannot be created or destroyed

• Energy can change form but cannot be transferred

Does the mechanical energy of an apple falling from a tree change?

• Yes, it increases

• Yes, it decreases

• No, it remains the same

• It depends on the height of the tree

What do the arrows in the figures mean?

• Direction of motion

• Magnitude of energy

• Change in energy

• Force applied

What does the symbol KE represent in the figure?

• Kinetic Energy

• Potential Energy

• Mechanical Energy

• Gravitational Potential Energy

Why is kinetic energy at its lowest at the top of the swing?

• Due to gravitational potential energy

• Due to friction

• Due to air resistance

• Due to the swing's position

Name other items that change electrical energy into thermal energy.

• Lightbulb

• Refrigerator

• Microwave

• Hairdryer

List three forms of energy that are involved in the running of a car engine.

• Electrical, Thermal, Radiant

• Chemical, Potential, Kinetic

• Mechanical, Gravitational, Elastic

• Nuclear, Solar, Wind

Circle the moving parts in the figure. What type of energy is this?

• Engine, Electrical Energy

• Wheels, Mechanical Energy

• Gases, Thermal Energy

• Spark Plug, Chemical Energy

How are work and power related?

• Work is the rate at which power is converted

• Power is the rate at which work is converted

• Work and power are unrelated

• Power is the total amount of work done

A 20 watt lightbulb uses 20 joules of energy every second. A person expends 50 joules of energy per stair when climbing up stairs. How long could you light the lightbulb if the energy used to climb 20 stairs were converted to electricity?

• 10 seconds

• 20 seconds

• 30 seconds

• 40 seconds