Energy Transformations

Which action in the science laboratory transforms chemical energy to thermal energy?

• Using a hot plate to boil a beaker of water

• Using a candle to melt sulfur in a test tube

• Growing potted plants near a window

• Flipping the light switch to turn on classroom lights

Which scenario describes a transformation of thermal energy into chemical energy?

• You turn on the heater in your car.

• The UV light from the Sun causes a sunburn.

• The Sun’s energy causes you to sweat.

• The oven bakes dough into bread.

A hydroelectric power plant works by using flowing water to turn a turbine. The turbine is connected to a magnet inside of a generator. When the magnet turns inside of the generator, the coiled wire surrounding the magnet will generate the type of energy that is sent along power lines to your home.

What energy transformation occurs in a hydroelectric power plant?

• Mechanical to electrical

• Electrical to mechanical

• Chemical to mechanical

• Chemical to electrical

When a cow eats grass, it chews the grass and then swallows it. The food ends up in the stomach where it is further broken down and absorbed. The energy and matter from the grass is used by the cow’s body to produce milk.What energy transformations occur in the cow during the entire process of using grass to produce milk?

• Chemical energy to mechanical energy

• Light energy to chemical energy

• Chemical energy to electrical energy to mechanical energy

• Chemical energy to mechanical energy to chemical energy

A flashlight battery is to light energy what a campfire is to —

• thermal energy

• electrical energy

• chemical energy

• nuclear energy

When a hawk eats a mouse and then uses the energy from the mouse to fly, the hawk’s body converts —

• mechanical energy to chemical energy

• thermal energy to mechanical energy

• chemical energy to mechanical energy

• mechanical energy to thermal energy

Which of the following describes the energy transformations that occur when a toaster is used to make toast?

• Thermal energy is transformed into chemical energy in the toaster, and chemical energy is transformed into thermal energy in the toast.

• Electrical energy is transformed into thermal energy in the toaster, and chemical energy is transformed into thermal energy in the toast.

• Light energy is transformed into thermal energy in the toaster, and thermal energy is transformed into chemical energy in the toast.

• Electrical energy is transformed into thermal energy in the toaster, and thermal energy is transformed into chemical energy in the toast.

A doorbell circuit converts electrical energy into mechanical energy. The mechanical energy is in the form of vibrations that ultimately produce

• chemical energy

• radiant energy

• sound energy

• thermal energy

The breakfast that a student ate provided energy for bicycling later in the day. Which energy transformation most likely occurred?

• radiant to nuclear

• chemical to nuclear

• radiant to mechanical

• chemical to mechanical

Amanda and Jake learned about kinetic and potential forms of energy within a simple electrical circuit. The circuit they are studying has a battery, wires, and a light bulb. Which is a form of potential energy in the circuit?

• chemical energy in the battery

• light energy from the light bulb

• heat energy lost from the electric wires

• electrical energy moving through the light bulb