<img src="https://d5nxst8fruw4z.cloudfront.net/atrk.gif?account=iA1Pi1a8Dy00ym" style="display:none" height="1" width="1" alt="" />

# Internal Combustion Engines

## Devices used to convert heat energy to kinetic energy with higher efficiency.

Estimated3 minsto complete
%
Progress
Practice Internal Combustion Engines

MEMORY METER
This indicates how strong in your memory this concept is
Progress
Estimated3 minsto complete
%
What's Under the Hood?

### What’s Under the Hood?

Credit: Freewheeling Daredevil
Source: http://farm3.staticflickr.com/2400/2263831989_b89c8f63d3_b.jpg

Racecars like this one have an internal combustion engine. It produces the power that runs the car at high speeds over the track.

#### Why It Matters

• Besides racecars, most other cars and trucks have internal combustion engines. In the majority of vehicles, the engine is under the hood.
• Credit: Andrew Taylor
Source: http://www.flickr.com/photos/profilerehab/5218108077/

There is a lot going on under the hood in addition to the engine [Figure2]

• Did you ever wonder how a car engine works? You probably know that most car engines burn gasoline, but how does that get the wheels to turn? Watch this video animation of an internal combustion engine to see what happens “under the hood:”

#### Can You Apply It?

1. Most car engines operate on a four-stroke cycle. What is the name of each stroke?
2. Outline what happens during each stroke of the four-stroke engine. Indicate whether the valves are open or closed, and describe what the piston does during each stroke.
3. Why does the heat of combustion push the piston down the cylinder in stroke 3? (Hint: One of the gas laws explains why.)
4. The piston moves up and down in a straight line, but the wheels turn in a circle. How does the movement of the piston cause the wheels to turn?

### Notes/Highlights Having trouble? Report an issue.

Color Highlighted Text Notes