Straw Rocketwith Launcher

with a Nod to Newton

Newton notes based upon NASA STEM Liaison, Janet Raines, Stomp Rocket presentation for the Oakley STEM Center.

What makes things move?Who was the first scientist credited with exploring how things move?

Galileo studied what makes things move, exploring:• falling objects – gravity – friction– forces

Galileo Galilei (1564-1642)

One scientist is known for the three physical laws he discovered. What is his name and what are his laws called?

Sir Isaac Newton (1642-1727)

Newton explained Galileo’s discoveries with his three “Laws of Motion.”

Newton’s 1st LawLaw of Inertia

• An object at rest tends to stay at rest.

• An object in motion will stay in motion at a constant speed in a straight line

unless acted on by a force.

*Inertia is the resistance to changes in motion.

Newton’s 2nd Law Law of *Acceleration

F=maForce = (*mass) x (acceleration)

• The more force on an object, the more it accelerates.

• The more massive an object is, the more it resists acceleration.

Mass – the amount of matter in an objectVelocity – speed and direction of a moving objectAcceleration - change in velocity with respect to time

Newton’s 2nd Law and RocketsLaw of Acceleration

• The more force (*thrust) from the rocket engine, the greater the acceleration.

• The lighter the rocket, the greater its acceleration for a given thrust.

Newton’s 3rd Law Law of Action/Reaction

When one object exerts a force on a second object, the second object exerts an equal but opposite force on the first object.

What is a rocket?• A rocket is a vehicle that is

self-contained and self-propelled.

• It achieves motion from Newton’s principle of a reaction resulting from every action.

Forces Acting on a Rocket

*

*

*

*

*Lift

Another View of Rocket Forces

How do Rockets demonstrate Newton’s 3 Laws of Motion?

1st Law: The rocket stays at rest until acted upon by a force. Once in motion, the rocket tends to stay in motion until acted upon by a force.

3rd Law: The thrust of the rocket fuel out of the rocket pushes it away from the Earth.

2nd Law: The greater the force exerted on the rocket, the greater its acceleration.

Building a Straw Rocket

• We can explore how a rocket works with a simple model built from a straw

• Instead of engines that fire to create the thrust force…

• We will use a rubber band launcher to create the thrust force

• Get ready!

Materials• Scissors• Roll clear tape• Rubber band• Popsicle stick –

large• Straw – generic

(can be flexible)• Ball of modeling

clay 1 cm diameter• Plastic coated

paper clip• Set of 2 fin

templates

Fin Template

Cut the straw so that you remove the flexible portion with the shorter end.

Discard

Fold paper clip into launch lug

Unfold paper clip into “S” Shape.

Fold ½ of the wide end of the “S” to form a 90° angle.

Do NOT create or attach the launch lug if you are using the Pitsco Straw Rocket launcher.

Attach paper clip to straw ½ cm from end.

Wrap tape around straw and paper clip at top and bottom of paper clip.

Do NOT create or attach the launch lug if you are using the Pitsco Straw Rocket launcher.

Press clay onto straw at launch lug end and form into a nose cone shape.

Be sure to press some of the clay into the straw so that you cannot shake it off easily.

Cut out and attach fins.

Cut out both fins – they look like arrow heads.

Wrap tape around straw at tip and shaft. (Tape should not intersect dotted lines.)

Attach second fin in same way.

Fold arrows at dotted lines to make 4 fins!

Create launcher.Stick a piece of tape parallel to and on the end of the popsicle stick.

Place a rubber band on the tape at the tip of the popsicle stick. Fold the tape over and onto the popsicle stick. Place one more piece of tape on in the same way.

Wrap a piece of tape perpendicular to and around the popsicle stick.

Do NOT create this launcher if you are using the Pitsco Straw Rocket launcher.

Launch the rocket!Hold the rocket parallel to the launcher. Hook the rocket to the rubber band using the launch lug.

Make sure you are not aiming at anything alive or breakable.Pull the rocket back to stretch the rubber band tight. Let go of the rocket!

Do NOT create this launcher if you are using the Pitsco Straw Rocket launcher.

Discover the answers• Does launch angle (the angle between horizontal

and line of popsicle stick launcher) affect the distance your rocket flies?

• Does the amount of stretch you have in your rubber band affect the distance your rocket flies?

• Does the mass of the nose cone affect the flight distance?

• Can you predict how far the rocket will fly based upon angle of launch and length of stretch in rubber band?