2nd Six Weeks Review

Select 3 examples of Newton's action-reaction law-

• a large magnet is placed near a piece of iron and the iron moves toward it
• hot gases blast out of the back of a jet engine and the jet accelerates forward
• car A crashes into the back of car B crumpling the hood of car A and the trunk of car B
• an angry student punches the wall putting a hole in the wall and breaking two of his fingers

Gary holds a backpack one meter above the ground. Which two forces would best represents this situation on a free body diagram?

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• 
• 
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A student pulls a 15.0 kg mass across a table with a spring scale and records a force of 60 newtons. What is the magnitude of the force exerted by the mass on the spring scale?

• 10 N
• 20 N
• 40 N
• 60 N

Force is an example of a vector and has-

• direction only.
• magnitude only.
• both direction and magnitude.
• neither magnitude nor direction.

Which of the following is true about friction with inclined planes versus flat surface?

• Friction is completely removed.
• Friction decreases.
• Friction increases.
• Friction does not change

An unbalanced force will cause an object to change its: (select 3)

• Shape
• Size
• Speed
• Mass
• Direction

A force that pulls in both directions is known as _________.

• weight force
• normal force
• tension force
• friction force

The force that always points to the center of a circular path is known as ______ force.

• tension
• centripetal
• centrifugal
• normal

When two forces act in the opposite direction, they are -

• add together
• subtracted from each other
• multiplied
• divided

Two forces, 160.3 N and 72.4 N, are acting on an object. What is the resultant force if the first acts upward and the second acts downward?

• 85.6 N down
• 87.9 N up
• 91.3 N down
• 97.9 N up