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.
Action-reaction forces can happen between
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.
List the 3 different types of fields mentioned in the text:
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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.
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.
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.
What does the law of universal gravitation describe?
If each object has the same mass, which pair has the strongest gravitational attraction?
Hint: The arrows represent force.
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.
What does the word "attract" mean? Provide an Example.
Sentence Starter: The word attract means...An example of attract or atrraction forces is..
What does the word "repulsion" mean? Provide an Example.
Sentence Starter: The word repulsion means...An example of repulsion or repulsion forces is..
If iron filings are sprinkled around the magnet, what will happen?
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.
Which of the following forces cannot act from a distance?
When a satellite is sent into space, what causes it to orbit a planetary body?
Each non-contact force has an area of influence surrounding it. What is this area called?
What causes a roller coaster to move?
The diagram below shows that ______________________.
Which answer best describes this image?
Which of the following statements is true?