Show:
Section 1 Gravity in Motion
Section 2 Newton's Laws of Motion
Section 3 Momentum
Applying Concepts
General Review
100
If Wil E. Coyote and a boulder fall off a cliff at the same time, which do you think will hit the ground first?
What is neither? Both will hit the ground at the same time because objects fall to the ground at the same rate because the acceleration due to gravity is the same for all objects.
100
Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first. Which of Newton's Laws is this?
What is Newton's Third Law of Motion/action and reaction?
100
What can happen to momentum when two objects collide?
When two objects collide, some or all of the momentum of each object can be transferred to the other object.
100
Think about a sport that uses a ball. Identify four examples from the sport in which an object is in projectile motion.
*Basketball: -a player jumping to dunk the ball -a ball passed between players -a ball shot toward the basket -a ball bounced on the floor before it hits the floor.
100
Explain IFA.
What is Newton's Laws? -inertia -force -action and reaction
200
______________is the motion of a body when only the force of gravity is acting on the body.
What is free fall?
200
The acceleration of an object depends on the mass of the object and the amount of force applied. Which of Newton's Laws is this?
What is Newton's Second Law of Motion/force?
200
___________ is a quantity defined as the product of the mass and velocity of an object.
What is momentum?
200
Use Newton's first law of motion to explain why airbags in cars are important during head-on collisions.
During a headon collision, an unbalanced force stops the motion of the car. But no unbalanced force immediately acts on the people inside the car. The people continue to move forward. Airbags are important because they provide unbalanced forces to stop the motion of the people in the car. The airbags prevent the people from hitting the dashboard or windshield of the car.
200
What does the magnitude of the gravitational force between two bodies depend on?
the mass of the bodies and the distance between them
300
_______________ gives an object in projectile motion its vertical motion.
What is gravity?
300
My mom is retired, but my brother refuses to let her just sit in the house. Johnny continually drags chickens, dogs, horses, and goats to her house for Mom to tend to. His theory is that if Mom just sits, her health will deteriorate due to lack of exercise. If she continues to be active, according to my brother, Mom will live a more productive life because she will still be able to care for herself and to attend to her daily needs. It's like the commercial, "A body in motion tends to stay in motion." This sounds like which of Newton's Laws?
What is Newton's First Law of Motion/inertia?
300
What are two ways that objects may interact after a collision?
After a collision, objects can stick together or can bounce off each other.
300
Give an example of an object with a small mass that has a large momentum. Explain your answer.
A fastball pitched by a baseball pitcher has as small mass but a large velocity. Therefore, the ball has a large momentum.
300
Friction acting on a rolling ball to eventually bring the ball to a stop is an example of which of the following? A. an unbalanced force B. gravity C. a balanced force D. momentum
A. an unbalanced force
400
The moon has no atmosphere. If an astronaut on the moon dropped a hammer and a feather at the same time from the same height, both would hit the moon's surface at the same time. Why?
The feather and the hammer are in free fall because there is no atmosphere.
400
Explain how the forces in each force pair are related.
The forces in a force pair are equal in size and opposite in direction.
400
Which of the following has the smallest amount of momentum? A. a loaded truck driven at highway speeds B. a track athlete running a race C. a baby crawling on the floor D. a jet airplane being towed toward an airport
C. a baby crawling on the floor; smallest weight and slowest speed
400
When you catch a softball, your hand and glove move in the same direction that the ball is moving. Analyze the motion of your hand and glove in terms of momentum.
The softball has momentum as it travels toward your glove. When the ball hits your glove, some of its momentum is transferred to your glove and your hand. As a result, your glove and hand move in the direction that the ball was moving before the catch.
400
In archery, you use a bow to shoot an arrow at a target. Why must an archer point the arrow a little above the target in order to hit the target in the center? What forces are involved?
Accept any of the following answers: The arrow moves in a curved path acccording to projectile motion. The arrow's horizontal velocity is constant if you ignore air resistance. The arrow's vertical velocity increases because gravity causes it to accelerate downward. The archer must aim slightly upwards of the target in order to compensate for acceleration due to gravity.
500
_____ ____________is a result of friction between the falling object and the air and also the inertia of the particles of the air. The air particles hasve to "move out of the way" of the falling object. Because the particles have mass, they also have inertia. Therefore, the air particles resist movment.
What is air resistance?
500
Imagine you accidentally bumped your hand against a table. Your hand hurts after it happens. Use Newton's third law of motion to explain what caused your hand to hurt.
Your hand hit the table with a certain amount of force. According to newton's third law of motion, the table exerts an equal and opposite force on your hand. The force exerted by the table causes your hand to hurt.
500
A car and a train are traveling with the same velocity. Do the two objects have the same momentum? Explain your answer.
The train has the greater momentum because it has the greatest mass.
500
To accelerate two objects at the same rate, the force used to push the object that has more mass should be A. smaller than the force used to push the object that has less mass. B. larger than the force used to push the object that has less mass. C. the same as the force used to poush the object that has less mass.
B. larger than the force used to push the object that has less mass
500
Use Newton's third law to explain how a rocket accelerates.
The hot gases expelled from the back of the rocket produce a reaction force on the rocket that accelerates it.