Energy in Systems Is Conserved Through Energy Transfers and Transformations

The total amount of energy in our universe -

• Can only change forms once.

• Can change and expand over time.

• cannot change but can transform into other forms.

Tags

NGSS.MS-PS3-5

What happens to the energy of a pendulum as its back-and-forth motion slows and the pendulum comes to a stop?

• The energy leaves the pendulum because the passing of time takes energy away from objects.

• The energy is transferred to the air because the pendulum pushes the air out of its path.

• The energy is transformed into potential energy as the pendulum comes to rest.

• The energy leaves the pendulum because the motion destroys energy.

Tags

NGSS.MS-PS3-4

NGSS.MS-PS3-5

Which statement best describes what happens to a snow skier's potential energy while gliding down a ski slope?

• Potential energy is conserved and has an equal value at the top and bottom of the slope.

• Potential energy is destroyed at a rate equal to the speed the skier travels down the slope.

• Potential energy is transformed into an equal amount of kinetic energy as the skier moves down the slope.

• Potential energy is created in an amount equal to the change in elevation as the skier moves down the slope.

Tags

NGSS.MS-PS3-2

NGSS.MS-PS3-5

Robin is swinging back and forth from a trapeze. In which of the following situations is her kinetic energy being transformed into potential energy?

• When her height is increasing and her speed is decreasing

• When her height ad speed are both equal to zero

• When her height is not changing and her speed is zero

• When her speed is increasing and her height is decreasing

Tags

NGSS.MS-PS3-4

NGSS.MS-PS3-5

Emma sings into a microphone. The sound is transferred from the microphone to a loudspeaker that is plugged into the wall. Her voice comes out of the loudspeaker and sounds much louder than before. In this system, sound energy is being transformed into ______________ energy and then back into ________________ energy.

• electrical; mechanical

• electrical; sound

• mechanical; sound

• heat; sound

A microwave works by focusing microwave light on the food inside of it. Which type of energy transformation takes place in a microwave?

• Light energy is transformed into electrical energy.

• Heat energy is transformed into electrical energy.

• Heat energy is transformed into light energy.

• Electrical energy is transformed into light energy.

How does a hydroelectric power plant demonstrate the Law of Conservation of Energy?

• The hydroelectric power plant is a good method of providing energy to many homes and businesses.

• The amount of water used in the hydroelectric power plant is equal to the amount of electrical energy used in a home.

• The amount of potential energy at the hydroelectric power plant is equal to the amount of electrical energy used in a home.

• The amount of kinetic and potential energy lost by the water is equal to the amount of electrical energy produced by the generator at he hydroelectric power plant.

Tags

NGSS.MS-PS3-5

Juan's room is suddenly dark when an incandescent light bulb burns out. He attempts to replace the old bulb with a new one but realizes that the old bulb is too hot to touch. Juan waits 10 minutes and then changes the bulb when it is completely cool. What happened to the heat in the bulb?

• The heat was completely destroyed.

• The heat was transferred to the air around it.

• The heat was transformed into electricity.

• The heat was stored as chemical energy.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-5

A moving bicycle has energy. What happens to the energy of the moving bicycle when the brakes are applied and it stops moving?

• It is released as chemical energy.

• It is stored as potential energy.

• It is transformed into heat energy.

• It is lost due to gravitational energy.

Tags

NGSS.MS-PS3-5

The Sun is the source of energy for producers. However, only about 10 percent of the energy is transferred from producers to consumers. What happens to the other 90 percent of the producers' energy?

• Some of it is destroyed, and some of it is returned into light energy.

• Some of it is destroyed, and some of it is stored as chemical energy.

• Some of it is released as heat energy, and some of it is stored as chemical energy.

• Some of it is released as light energy and some of it is stored as chemical energy.

Tags

NGSS.MS-LS2-3