Bernoulli Effect
Bernoulli's Principle is a physical principle formulated by Daniel Bernoulli which states that as the speed of a moving fluid (liquid or gas) increases, the pressure within the fluid decreases.
Objective: This experiment will show the relationship between velocity and pressure of a fluid. The demonstrations should be appropriate for all levels. The explanations may be more suitable for upper level and high school.
Materials Needed:
1. Ruler, strip of paper (about 2.5 x 5 cm)
2. 2 aluminum cans connected by a string (about 1 m long), thumb tack or tape, ruler.
3. Thread spool, straight pin, and index card
4. Funnel and a ping-pong
Procedures:
1. Tape the paper to the ruler so that it forms an airfoil (like the wing of an airplane). Place a pencil on a table and place the midpoint of the ruler across the pencil, form a "t" shape. Blow across the top of the paper.
Airfoil
2. Hang the cans so they are at the same level and about 2 cm apart. Hold a ruler behind the cans and blow air between the cans. (This also works with two apples or two balloons).
3. Stick the pin through the index card and then into the hole on one side of the spool. Blow into the other side of the spool.
4. Place the ping-pong ball in the funnel. (The top part of a plastic bottle makes a good funnel.) Blow through the small end of the funnel.
Explanations:
1. The air above the air foil is faster than the air below. The higher pressure below pushed the air foil up.
2. The air between the cans is faster than the air on the sides. The higher pressure on the sides pushes the two cans together.
3. The air between the spool and card is faster than the air on the
opposite side of the card. The higher pressure on
the opposite side pushes the card against the spool.
4. The air is faster below the ball and on the sides. The higher pressure above the ball pushes the ball down into the funnel.
By Ashunda Williams
References:
1. Bernoulli Effect lesson
2. Aviation History
Click Here for more physics lessons from the SMILE program.
Objective: This experiment will show the relationship between velocity and pressure of a fluid. The demonstrations should be appropriate for all levels. The explanations may be more suitable for upper level and high school.
Materials Needed:
1. Ruler, strip of paper (about 2.5 x 5 cm)
2. 2 aluminum cans connected by a string (about 1 m long), thumb tack or tape, ruler.
3. Thread spool, straight pin, and index card
4. Funnel and a ping-pong
Procedures:
1. Tape the paper to the ruler so that it forms an airfoil (like the wing of an airplane). Place a pencil on a table and place the midpoint of the ruler across the pencil, form a "t" shape. Blow across the top of the paper.
Airfoil
- Pressure is reduced is due to the smaller space the air has above the wing
than below. Air cannot go through the wing, so it must push around it. The
surface air molecules push between the wing and outer layers of air. Due to the
bump of the airfoil, the space is smaller and the molecules must go faster.
According to Bernoulli's Law, faster air has lower air pressure, and thus the
high pressure beneath the wing pushes up to cause lift.
2. Hang the cans so they are at the same level and about 2 cm apart. Hold a ruler behind the cans and blow air between the cans. (This also works with two apples or two balloons).
3. Stick the pin through the index card and then into the hole on one side of the spool. Blow into the other side of the spool.
4. Place the ping-pong ball in the funnel. (The top part of a plastic bottle makes a good funnel.) Blow through the small end of the funnel.
Explanations:
1. The air above the air foil is faster than the air below. The higher pressure below pushed the air foil up.
2. The air between the cans is faster than the air on the sides. The higher pressure on the sides pushes the two cans together.
4. The air is faster below the ball and on the sides. The higher pressure above the ball pushes the ball down into the funnel.
By Ashunda Williams
References:
1. Bernoulli Effect lesson
2. Aviation History
Click Here for more physics lessons from the SMILE program.