3.5.2 pratice : forces

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1.Define the term "force." (1 point)
A push or pull that causes change in motion of an object.



2.Give an example of a "balanced force" and explain what makes it a balanced force. (3 points)

equal forces that act on a single object in opposite directions and cancel each other out.
Ex. tug of war.



3.What are the Newton's three laws of motion? (6 points)
1. An object will maintain its state of a straight line motion until acted upon by an unbalanced force.
2. An object's acceleration is directly related to the net force applied and inversely related to the mass of the object
3.When one object exerts a force on a second object, the second object always exerts a force back on the first object that's equal in magnitude and opposite in direction.



4.Define the term "inertia" and describe an example of a situation where inertia is present. (2 points)

The property of a body that resists any change to its uniform straight motion.



5.Calculate the force it would take to accelerate a 250 kg motorcycle at a rate of 5 m/s2. (1 point)

1,250 neutons



Friction:
1.Define friction. Name and describe two kinds of friction. (4 point)

The force that opposes motion when two materials touch each other.
1.Static friction
2.kinetic friction

2. What are the two factors that determine the strength of the force of friction between two sliding objects? (2 points)





3 A. What does the "coefficient of friction" tell you? (3 points)
A number that compares friction force to the force pushing two surfaces together.




B. Give an example of two surfaces that would have a low coefficient of friction. (1 points)

waxed ski on snow
wood on wood


C. Give an example of two surfaces that would have a high coefficient of friction. (1 point)

rubber on concrete
steel on aluminum


Centripetal Force:
1.Define the term "centripetal force." (1 point)





2.Give an example of "centripetal acceleration." (1 point)

acceleration toward the center of a circular path



3.A. What is the difference between linear motion and circular motion? (2 points)


you go in a line and a circle?


B. Give an example of each type of motion. (2 points)





4.Why does the moon orbit Earth as opposed to the sun? (2 points)





5.What is the Universal Law of Gravitation? (1 point)





6.What two factors influence the attraction between objects? (2 points)





Buoyant Force:
1.Describe Archimedes' Principle. (2 points)





2.Describe the two opposing forces acting on an object floating in water. (2 points)





3.A. Define the term "density." (1 point)





B. What two factors determine the density of a fluid? (2 points)





4.Explain how a heavy boat floats on water. (4 points)





5.From what you have learned about buoyancy, how does a submarine submerge and then float on water? (4 points)

[Williams, Sue]

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[Williams, Sue]

[Williams, Sue]

[djshotte...@gmail.com]

what about the rest of the questions?