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How To: Understand The Law Of Conservation Of Energy

The law of conservation of energy can be difficult to understand. Fear not, A Moment of Science is here to help!

Photo: JAS_photo (Flickr)

The law of conservation of energy is simple to understand once you take the time to explore it.

There’s a rule in physics called the law of the conservation of energy. Energy can neither be created out of nothing, nor disappear into nothing — all it does is change forms. That sounds simple, but it confused people for a long time.

Energy Is Lost

To see why, let’s think of an easy example, and then a harder one. You roll an eight ball across a billiard table. When it hits the cue ball, the cue ball starts moving and the eight ball stops.

Why? Because the kinetic energy you put into the eight ball with your hand has been passed into the cue ball. Notice that no energy is lost, it just traded places.

Changing Forms

Okay, that was easy. Now suppose you see a car going down the street at a constant speed. Suddenly the driver slams on the brakes. The car comes to a halt. Where did the energy go?

Unlike the eight ball situation, the energy seems to have vanished! In fact, we now know that the energy merely changed forms.

Kinetic to Sound

When the driver hit the brakes, what else happened?

For one thing, there was a loud screeching noise. That’s kinetic energy being converted into sound waves.

The brakes and the skidding tires became hot. That’s kinetic energy being converted into heat. Pebbles were knocked out of the way. That’s a mini-version of the billiard balls — kinetic energy being passed from one object to another.

Energy Can Change Forms, But Can’t Disappear

All these little outlets add up to exactly as much kinetic energy as the car had in the first place. It works out just the way the law of the conservation of energy says: energy can change forms, but can’t ever disappear.

• Anonymous

remember kinetic energy can also be used to produce renewable energy such as electric.
Buddy T
Owner of – kinetic energy

• http://www.hi.com/ Jyc

Science

• http://www.hi.com/ Jyc

Science science

• http://www.hi.com/ Jyc

Science science science

• http://www.hi.com/ Jyc

O_O -… So this was posted 4 years ago?

• http://www.hi.com/ Jyc

Photo: JAS_photo (Flickr)
The law of conservation of energy is simple to understand once you take the time to explore it.

There’s a rule in physics called the law of the conservation of energy. Energy can neither be created out of nothing, nor disappear into nothing — all it does is change forms. That sounds simple, but it confused people for a long time.

Energy Is Lost

To see why, let’s think of an easy example, and then a harder one. You roll an eight ball across a billiard table. When it hits the cue ball, the cue ball starts moving and the eight ball stops.

Why? Because the kinetic energy you put into the eight ball with your hand has been passed into the cue ball. Notice that no energy is lost, it just traded places.

Changing Forms

Okay, that was easy. Now suppose you see a car going down the street at a constant speed. Suddenly the driver slams on the brakes. The car comes to a halt. Where did the energy go?

Unlike the eight ball situation, the energy seems to have vanished! In fact, we now know that the energy merely changed forms.

Kinetic to Sound

When the driver hit the brakes, what else happened?

For one thing, there was a loud screeching noise. That’s kinetic energy being converted into sound waves.

The brakes and the skidding tires became hot. That’s kinetic energy being converted into heat. Pebbles were knocked out of the way. That’s a mini-version of the billiard balls — kinetic energy being passed from one object to another.

Energy Can Change Forms, But Can’t Disappear

All these little outlets add up to exactly as much kinetic energy as the car had in the first place. It works out just the way the law of the conservation of energy says: energy can change forms, but can’t ever disappear.

• http://www.hi.com/ Jyc

Screeeech!

• http://www.hi.com/ Jyc

O_O

• http://www.hi.com/ Jyc

あなたはワッフルが好きですか？はい、私たちはワッフルが好き！あなたはパンケーキが好きですか？はい、私たちはパンケーキが好きです！あなたはフレンチトーストが好きですか？はい、我々はフレンチトーストが好き！斗ダダ斗は、口がいっぱいに得るために待つことができない！ワッフル！

• http://www.hi.com/ Jyc

Pinkie pie is cool!

• http://www.hi.com/ Jyc

It must suck to be energy. It’s always moving around. It never has time to sit and play Smash Bros or Kirby’s Nightmare in Dreamland Wii…

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Jyc is cool!

• http://www.hi.com/ Jyc

I like this website! I found a post about what makes meat tender! Mmmm… Meat.

• http://www.hi.com/ Jyc

Mmm… I still like meat!

• http://www.hi.com/ Jyc

I feel ya. It wouldn’t be able to play Kirby Triple Deluxe, either.

• http://www.hi.com/ Jyc

Yeah… That would suck.

• http://www.hi.com/ Jyc

Hi

• http://www.hi.com/ Jyc

I try to leave this page, but I always come back because it is so interesting.

• http://www.hi.com/ Jyc

Why the O_O face?

• http://www.hi.com/ Jyc

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A Moment of Science
How To: Understand The Law Of Conservation Of Energy
By WILLIAM OREM
Posted July 29, 2010

The law of conservation of energy can be difficult to understand. Fear not, A Moment of Science is here to help!

Listen Now: How To: Understand The Law Of Conservation Of Energy0:00

Photo: JAS_photo (Flickr)
The law of conservation of energy is simple to understand once you take the time to explore it.

There’s a rule in physics called the law of the conservation of energy. Energy can neither be created out of nothing, nor disappear into nothing — all it does is change forms. That sounds simple, but it confused people for a long time.

Energy Is Lost

To see why, let’s think of an easy example, and then a harder one. You roll an eight ball across a billiard table. When it hits the cue ball, the cue ball starts moving and the eight ball stops.

Why? Because the kinetic energy you put into the eight ball with your hand has been passed into the cue ball. Notice that no energy is lost, it just traded places.

Changing Forms

Okay, that was easy. Now suppose you see a car going down the street at a constant speed. Suddenly the driver slams on the brakes. The car comes to a halt. Where did the energy go?

Unlike the eight ball situation, the energy seems to have vanished! In fact, we now know that the energy merely changed forms.

Kinetic to Sound

When the driver hit the brakes, what else happened?

For one thing, there was a loud screeching noise. That’s kinetic energy being converted into sound waves.

The brakes and the skidding tires became hot. That’s kinetic energy being converted into heat. Pebbles were knocked out of the way. That’s a mini-version of the billiard balls — kinetic energy being passed from one object to another.

Energy Can Change Forms, But Can’t Disappear

All these little outlets add up to exactly as much kinetic energy as the car had in the first place. It works out just the way the law of the conservation of energy says: energy can change forms, but can’t ever disappear.

Tags

billiard balls, energy, kinetic energy, the law of the conservation of energy
Related Posts (Automatically Generated)

Screeeech!
Potential Energy
Swinging Physics: Potential And Kinetic Energy Working Together
Heat Is A Measure Of Kinetic Energy

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