Balloon Jets and Helicopters

Miss Laverty 2012

March 20th, 2012

Instructions:1) Hand out the

workbooks2) Grab today’s handout

Today’s Agenda • Balloon Jets• Helicopters• Rotor-Copters

Balloon Jets

• Materials: balloon, straw, string and tape • Procedure:

1. Thread the straw onto the line of string2. Blow up the balloon, but do not tie the end3. Tape the inflated balloon onto the straw 4. Have one person hold one end of the string, and

another person hold the other 5. Release the balloon 6. Observe and record results

Balloon Jets Diagram:• high pressure, low pressure, thrust, gravity, drag and lift. • Arrows to show the direction of air flow and the direction of

propulsion.

Balloon Jets

• What makes the balloon jet travel forward? – The escaping air was the balloon’s means of

propulsion – This is similar to how a jet engine works

Helicopters

• The blades are shaped just like a wing to give the helicopter lift. This shape is called an airfoil

• The rotor blades work very similar to airplane wings. • Airplane wings travel through the air at high speeds.

The rotor blades of helicopters spin at high speeds to create lift, even when the helicopter isn’t moving forward

• To go forward the pilot can tilt the main rotor blade forward

Helicopters

Helicopters

Helicopters

Helicopters

Helicopters

Helicopters

• When the toy is released the air pushes up slightly on the blades

• This causes the blades to bend up • The toy spins because the force of the air is

the same on both blades

The four forces of flight

•Lift•Thrust•Drag•Gravity

Title Pages

• Air takes up space and exerts pressure• Air is fluid and can be compressed• Air is composed of different gases• Bernoulli’s Principle• Overcoming gravity with lift