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C5 - Contact Forces vs. Forces At-A-Distance

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Last updated over 3 years ago
26 questions
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Action-reaction paired forces can occur between objects in direct contact (contact forces) or between objects that are not touching (action-at-a-distance forces). Examples of contact forces are colliding football players, car wrecks, or playing tug-of-war.
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Fields around objects, such as a gravitational field, an electric field, or a magnetic field, can cause interactions between objects even without the objects touching. When objects interact due to gravitational, magnetic, or electrical forces, the forces are called “action-at-a-distance forces” and can cause objects to interact even from a distance. The resulting action-reaction forces between the interacting objects are equal in magnitude and opposite in direction.
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Distinguish the force from the effect of the force when considering forces acting at a distance. Forces, such as gravitational, electrical, and magnetic, act at a distance; however, their effect depends on mass and distance.
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Gravitational force: The action-reaction of gravitational force
pairs at a distance are equal and opposite. The motion effect of
the pair is dependent upon the mass and strength of the gravitational field.

A roller coaster car moving down a hill is not in direct contact with Earth, yet action-reaction forces exist between them. The car exerts a gravitational pull on Earth, and Earth exerts an equal and opposite pull on the car. However, the effect of those forces depends on mass. The mass of the car is so small compared to the mass of Earth that the net effect is the car accelerating down the hill.
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The Moon’s orbit around Earth is an example of action-reaction
and at-a-distance gravitational force. The Moon pulls on Earth,
while Earth pulls on the Moon; however, the effect on the two
objects (motion of orbit) is different due to the large mass of Earth and the smaller mass of the Moon.
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Question 19
19.

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Question 26
26.

Question 2
2.

Question 3
3.

Question 4
4.

Question 7
7.

List the 3 different types of fields mentioned in the text:

*
*
*

Question 9
9.

Question 10
10.

Question 12
12.
Forces that act a _____________ include gravitational, _______________, and magnetic. However, their effect depends on their _________ and distance.
Other Answer Choices:
mass
distance
electrical
Question 14
14.
A roller coaster moves down primarly by __________________ force. The motion of this gravitational force is dependent upon the _________ and strength of the gravitational __________. Inerestingly enough, the roller coaster moving down is ________ in contact with the Earth (indirect contact) but still action and _____________ forces exist.
Other Answer Choices:
not
mass
gravitational
field
reaction
Question 15
15.

Question 17
17.
Word bank:
orbit
Newton's
masses
Earth
opposite
reaction
Law

The Moon orbit's around the _______. This is an example of action-_______ and at-a-distance gravitational force.

The Earth pulls on the Moon and the moon pulls on the Earth with in an equal and _______ way according to _______ third _______ . The effect the Earth and moon has on each is different however because they have different _______. The moon is smaller and will _______ around the bigger Earth.
Question 18
18.

If each object has the same mass, which pair has the strongest gravitational attraction?
Hint: The arrows represent force.
The first, because it appears to weigh the most.
The first, because the arrows are thinest.
The  second, because it has an even balance of weight and distance.
The first, because the objects are closest together.
Electrical and magnetic forces: Objects with magnetic fields can
also exert action from paired forces at-a-distance. Magnets can
attract or repel.

Electrically charged objects with electric fields also exert paired action-at-a-distance attraction or repulsion forces between objects. The resulting motion depends on the strengths and charges of the magnetic or electrical fields and the mass of the particles.


Question 21
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What does the word "attract" mean? Provide an Example.

Sentence Starter: The word attract means...An example of attract or atrraction forces is..

Question 22
22.

What does the word "repulsion" mean? Provide an Example.

Sentence Starter: The word repulsion means...An example of repulsion or repulsion forces is..

Question 23
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Question 24
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Question 25
25.

If iron filings are sprinkled around the magnet, what will happen?

The filings will move away from the magnet's field.
The filings within the magnetic field will show an attraction between the north and south poles.
The filings within the magnetic field will show how the 2 ends of the magnet are repulsive.
The filings will not create a pattern.
Action-reaction forces can happen between
objects that are both touching directly and/or not touching directly
objects that are not touching (indirect contact) only
objects that are touching (direct contact) only
What are some examples of action-reaction paired contact forces?
<Select all that apply>

Hint: Contact means touching. Think about things that are touching directly.
A snowflake is falling due to gravity.
A magnet is used to pull a nail towards it without the nail touching the magnet.
A hammer hitting a nail into a wooden board
A cat scratching a wooden post.
Which of the following forces cannot act from a distance?
gravity
kinetic friction
magnetism
electricity
When a satellite is sent into space, what causes it to orbit a planetary body?
The force of thrust sends it into orbit around the planet
The planet's magnetic pull attracts the object into the field
The satellite enters the planet's gravitational field and falls into orbit around it
Satellites do not orbit a planet they only pass near planets on their journey through space
Each non-contact force has an area of influence surrounding it.  What is this area called?
influence center
gravitational attraction
field
attraction
What causes a roller coaster to move?
The action of magnets poles forcing the car forward while opposite pole magnets slow them down.
The action of electricity powering the reaction-movement of the car. The car goes equal to the amount of energy applied.
The action of the car exerting a gravitational pull on the Earth, and the Earth's equal and opposite reaction of pulling on the car toward the mass of the Earth.
What does the law of universal gravitation describe?
An object's gravitational pull is determined solely by the amount of mass it contains.
Objects repel each other if their mass is too small or their distance is too great.
All objects experience gravity based on the amount of magnetism they encompass.
Objects are attracted to one another based on the distance between them and their masses.
The diagram below shows that ______________________.
Electric forces are only slightly affected by distance.
As distance increases, the electric force decreases.
As distance decreases, the objects become less attractive.
As distance increases, the electric force increases.
Which answer best describes this image?

The positively charged red object will be attracted to the negatively charged blue object.
The blue charged object will repel the negatively red charged object.
The positive charge is repelling the negative charge.
Which of the following statements is true?
When an object gains electrons, its negative charge increases.
When an object gains electrons, its positive charge increases.
When objects gain protons, they become positively charged.
When objects transfer neutrons, the charge increases.