Newton's Third Law
Lesson 4
Newton’s Third Law
Scan Lesson 4. Then write three questions that you have about Newton’s third law of motion in your Science Journal. Try to answer your questions as you read.
Predict the corresponding result for each force.
Opposite Forces I found this on page
.
Force
Result
An airplane’s jet engine pushes air toward the back of the plane.
A fisherman tosses an anchor away from his boat.
A skier digs ski poles into the snowy ground and pushes down and backward.
words.
I found this on page
.
I found this on page
.
Define force pair, and identify the 2 parts of a force pair. Force pair:
20
The Laws of Motion
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Summarize Newton’s third law of motion in your own
Newton’s Third Law of Motion
Lesson 4 | Newton’s Third Law (continued)
I found this on page
.
Compare forces in a force pair. Action force
Reaction force
Size Direction
I found this on page
.
Analyze why force pairs do not cancel each other. equal and opposite forces
equal and opposite forces
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
applied on the same object
force pair
I found this on page
.
Summarize the comparison above.
I found this on page
.
Classify forces in the sentences below. Underline action forces; circle reaction forces. A swimmer pushes his arms back against the water in a pool, and the water pushes forward against his arms. A rocket engine pushes hot gas out in a downward direction, and the hot gas pushes upward on the engine. A trampoline hurls a girl into the air. The Laws of Motion
21
Lesson 4 | Newton’s Third Law (continued)
Using Newton’s Third Law of Motion I found this on page
Model Newton’s third law of motion in a drawing. Label these terms: .
• force
• force pair
Define momentum.
I found this on page
.
I found this on page
.
Explain the equation for momentum. p=m×v
p stands for
22
The Laws of Motion
m stands for
v stands for
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Momentum
• action force
Lesson 4 | Newton’s Third Law (continued)
I found this on page
.
Analyze momentum. Determine the momentum for each object. Circle the object that would be more difficult to stop. a 10-kg shopping cart moving at 5 m/s
Summarize the law of conservation of momentum.
Conservation of Momentum I found this on page
a 2-kg ball moving at 28 m/s
.
The
momentum of a group of objects
act on the objects.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
I found this on page
.
Contrast types of collisions. Inelastic
Elastic Both objects collide momentum conserved
If you have ever been in a car at a stoplight beside a large truck, you probably noticed that the car took off from the stop much more quickly than the truck. Explain why it is harder to start and stop the motion of a large truck than that of a small car.
The Laws of Motion
23
Newton’s Third Law
Scan Lesson 4. Then write three questions that you have about Newton’s third law of motion in your Science Journal. Try to answer your questions as you read.
Predict the corresponding result for each force.
Opposite Forces I found this on page
.
Force
Result
An airplane’s jet engine pushes air toward the back of the plane.
A fisherman tosses an anchor away from his boat.
A skier digs ski poles into the snowy ground and pushes down and backward.
words.
I found this on page
.
I found this on page
.
Define force pair, and identify the 2 parts of a force pair. Force pair:
20
The Laws of Motion
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Summarize Newton’s third law of motion in your own
Newton’s Third Law of Motion
Lesson 4 | Newton’s Third Law (continued)
I found this on page
.
Compare forces in a force pair. Action force
Reaction force
Size Direction
I found this on page
.
Analyze why force pairs do not cancel each other. equal and opposite forces
equal and opposite forces
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
applied on the same object
force pair
I found this on page
.
Summarize the comparison above.
I found this on page
.
Classify forces in the sentences below. Underline action forces; circle reaction forces. A swimmer pushes his arms back against the water in a pool, and the water pushes forward against his arms. A rocket engine pushes hot gas out in a downward direction, and the hot gas pushes upward on the engine. A trampoline hurls a girl into the air. The Laws of Motion
21
Lesson 4 | Newton’s Third Law (continued)
Using Newton’s Third Law of Motion I found this on page
Model Newton’s third law of motion in a drawing. Label these terms: .
• force
• force pair
Define momentum.
I found this on page
.
I found this on page
.
Explain the equation for momentum. p=m×v
p stands for
22
The Laws of Motion
m stands for
v stands for
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Momentum
• action force
Lesson 4 | Newton’s Third Law (continued)
I found this on page
.
Analyze momentum. Determine the momentum for each object. Circle the object that would be more difficult to stop. a 10-kg shopping cart moving at 5 m/s
Summarize the law of conservation of momentum.
Conservation of Momentum I found this on page
a 2-kg ball moving at 28 m/s
.
The
momentum of a group of objects
act on the objects.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
I found this on page
.
Contrast types of collisions. Inelastic
Elastic Both objects collide momentum conserved
If you have ever been in a car at a stoplight beside a large truck, you probably noticed that the car took off from the stop much more quickly than the truck. Explain why it is harder to start and stop the motion of a large truck than that of a small car.
The Laws of Motion
23
