2.1 Energy & Energy Transformations Review

What is/are the energy transformation(s) that take place when using a wind turbine to generate usable energy?

• friction - electrical

• kinetic - mechanical - electrical

• friction - mechanical - electrical

• mechanical - friction - electrical

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NGSS.MS-PS3-5

Wind turbines can generate a great deal of usable energy and have become popular because there is no cost to use wind and they do not emit greenhouse gases. A typical wind turbine is only 30% efficient, though. Explain what has happened to the other 70% of the energy.

• It is lost due to friction.

• It is converted to thermal energy.

• It is stored as potential energy in the turbine.

• It is released as mechanical energy into the air.

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NGSS.MS-PS3-5

According to the law of conservation of energy, energy is not created or destroyed. It changes form or is transformed. What energy transformation(s) is/are depicted here?

• electrical energy ⇒ light energy

• potential energy ⇒ kinetic energy ⇒ light energy

• chemical energy ⇒ electrical energy ⇒ light energy

• Chemical energy ⇒ electrical energy ⇒ heat and light energy

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NGSS.MS-PS3-4

Electrical energy is used to turn the blades of a fan. The amount of energy transformed is seen here: 750 J electrical energy is transformed into 400 J kinetic or mechanical energy. What happened to the remaining 350 J of energy?

• It was lost due to friction.

• It was transformed into 350 J of heat energy.

• It was destroyed by the rotating blades of the fan.

• It was never used and therefore was not transformed.

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NGSS.MS-PS3-5

Jenna built a completed electrical circuit. Jenna’s circuit illustrates what energy transformation?

• Electrical energy decreases over time.

• Electrical energy does not affect heat or light.

• Electrical energy can be transformed into both heat and light.

• lElectrical energy can be transformed only into light.

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NGSS.MS-PS3-5

Muscles convert chemical energy into

• light energy.

• nuclear energy.

• mechanical energy.

• electromagnetic energy.

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As the band passed by, the beating drums and trumpets made Billy feel like his body was beating with the music. He could hear the music and he could feel it!

How would a scientist explain this to Billy?

• Sound waves cannot travel through the air

• Sound waves transmit energy through all forms of matter

• The marching causes the ground to move which Billy feels

• Sound waves are transmitted faster through gases than through solids.

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NGSS.MS-PS4-2

The phrase and diagram represent an important law in science.

That is

• energy on Earth is transferred to Earth by radiation.

• matter is never created or destroyed; it only changes form.

• all matter has an attractive force that is dependent on its mass.

• energy is never created or destroyed; it only changes form.

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Which would be the best example to demonstrate the principle of conservation of energy?

• a stone is crushed

• light bends around a sharp edge

• a pendulum swings back and forth

• a balloon inflates when air is blown into it

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In the 19th century James Joule, an English scientist, was the first to recognize the mechanical equivalent of heat as a specific form of the general rule of the conversion of one form of energy to another.

Which fact can be explained with the help of this law?

• burning a fuel releases heat

• heating a block of ice causes it to melt

• a piece of iron glows red hot in a furnace

• wood rubbed against a rough surface feels hot

Tags

NGSS.MS-PS3-5

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