Download 45 Newton`s Laws Introduction

NEWTON’S LAWS LESSON: 4/19/05
1. The propeller pushes air backwards. The air pushes back on the propeller.
A. Which of the forces shown above represents the air pushing back on the propeller?
B. The thrust is the ___________ force and the _________ force is the air being forced
backwards by the propeller.
C. If the gravity ( weight) exactly matches the lift, will the airplane go up, down, or stay at the
same altitude? _______________________________________________________.
D. Which one of Newton’s three laws explains this statement, “if the propeller pushes air
backwards then the air pushes back on the propeller with an equal force in the opposite
direction.”? ________________
2.
A. What is the net force acting on each cart? Cart A__________ Cart B_____________
B. What is the total mass of each cart? Cart A__________ Cart B_____________
C. Calculate the acceleration of each cart (from f=ma we get a=f/m)
Cart A__________ Cart B_____________
D. Explain what happens to the cart’s acceleration if the net force is kept constant and the
mass
of the cart is increased?
E. Which of Newton’s three laws of motion explains what happens in D?
3.
A. What is the acceleration of the cart in diagram A? _________m/s2
B. Suppose the mass of this cart remains the same and the net force is doubled. What
effect will this have on the acceleration of the cart?
C. Which of Newton’s three laws of motion explains your answer in B?
NEWTON’S LAWS LESSON: 4/19/05
4. Refer to the diagram labeled “A”. If the cart is moving to the right at 3.0m/s, what will
happen to the 10kg weight sitting on the top of the cart if the cart stops abruptly?
5. Look up Bernoulli’s Principle in your text. What is the significance of Bernoulli’s
Principle with respect to an airplane?
NEWTON’s Three Laws of Motion
1. Sometimes called the law of inertia. This law states:
An object at rest will remain at rest and an object in motion will continue in
motion at constant velocity, unless acted upon by a net force greater than 0N.
2. This law really states three things. Each is identified here by a superscript. This law,
stated mathematically is F=ma
1A force acting on an object will cause the object to accelerate in the direction of the
force, the 2acceleration being proportional to the force, and 3inversely proportional
to the mass of the object.
3. This law is often referred to as the Law of Action and Reaction.
Forces occur in pairs, equal in magnitude and opposite in direction.
BERNOULLI’S PRINCIPLE
Use the airfoil diagram to show ( Label) where:
A. The air velocity is “high” and “low”.
B. The pressure is “high” and “low”.
C. The pressure is “high” and “low”.
D. Label the weight vector and the lift vector, and the thrust and drag vectors.
E. What is an airfoil?
NEWTON’S LAWS LESSON: 4/19/05
INSTRUCTIONS FOR THE HYBRID PAPER AIRPLANE
Step 1
Fold an 8 1/2 x 11 inch sheet of paper
down the middle of the long dimension.
Don't panic. Just look at the pictures. On the
left I'll show you what you're starting with,
and I'll mark (in blue) where you're going to
fold. On the right you'll see what you should
end up with after each step.
Step 2
Next fold the two upper corners in at a 45degree angle. Be careful here to line these
up, and do not let the flaps cross the middle
of the paper. Use the middle fold as a guide.
Step 3
Fold the upper point over and crease.
Step 4
Next fold the new upper corners in at a
45-degree angle. Be careful here to line
these up, and do not let the flaps cross the
middle of the paper. Use the middle fold as a
guide.
Step 5
Undo step 4. (We need the creases for the
next step)
NEWTON’S LAWS LESSON: 4/19/05
Step 6
Using those creases as a guide, fold the
corners as shown. What we are doing is
building up an airfoil at the leading edge of
the wing.
Step 7
Using the edge of paper as a guide, fold
the corners again, as shown.
Step 8
Make the final fold for the wing leading
edges.
Step 9
Fold the tip over. Look closely at the
drawing, don't fold too much, we just want
to take the sharp edge off the nose.
Step 10
Fold the plane in half.
The angled lines below the picture show
what the plane would look like from the
back.
Step 11
Fold the wing over to form the fuselage.
Make the body nice and even. (You can see
that it's even if the trailing edge of the wings
makes a nice straight line)
Step 12
Flip the plane over, and fold the other
wing.
NEWTON’S LAWS LESSON: 4/19/05
Step 13
Lay the plane out flat.
Step 14
Fold the winglets as shown. Make them
about 3/4 of an inch (About 20 mm).
Project #1: BUILD A HELICOPTER
1. Cut the pattern out then cut down the center dotted line only as far as indicated tn the
diagram above. You may want to write your name on your helicopter.
2. Fold the two “wings” outward in opposite directions as shown in the diagram below.
Place a paperclip on the bottom of the helicopter as shown.
NEWTON’S LAWS LESSON: 4/19/05
3. To fly the helicopter, either throw it upward paperclip end first OR you can drop it from
some height…like off the Shark balcony
HOW DOES THIS APPLE Y TO THE REAL WORLD?
 Maple Tree seeds are nature own helicopters! Here is a picture of Maple seeds as they come
from the tree.
These seeds twirl as the fall from the tree. This helps them disperse better in the environment.
Question : Where does the leaf get it’s lift?