# Ch. 1 Sections 2&3 Review

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Write the type of KINETIC FRICTION SHOWN
BELOW.
friction?

friction questions.
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ANSWER THE QUESTIONS ON THE PAPER
THAT WAS PASSED OUT TO YOU.
A combination of all forces
that act on an object.
Friction is a force between
any two surfaces, that
opposes motion.
Unbalanced force
a)
The water is a lubricant that
when spilled, fills in the hills and
valleys on the floor and reduces
the floor
Newtons
Friction occurs because
surfaces are covered with
microscopic “hills and
valleys” that stick to each
other when they come in
contact.
 Rough Surfaces have more
hills and valleys that increase
the force of friction. Smooth
surfaces have less hills and
valleys, therefore less friction
occurs.
These surfaces will have
more friction because
they have larger hills and
valleys than the other
picture. This means they
are more rough.
If the force pushing the
two surfaces together is
great, the hills and valleys
are in closer contact and
friction increases.
More Force = More Friction
Make a surface rougher
Push surfaces together
harder
Kinetic- sliding a book
across the tabletop
Static- pushing a piece of
furniture and it not
moving.


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Sliding Kinetic Friction- moving a book across
a desk, applying brakes in a car, scratching
Rolling Kinetic Friction- wheels of a bike, toy
car, trains on a track
Fluid Kinetic Friction- oil lubricating parts on
a plane, car, or bike, water flowing through a
hose
Two young girls are fighting over a present. One is pushing is with a force of 10N to the right and the other is
pushing with a force of 50 N to the left. Use the picture below to answer the questions that follow.
1.The forces shown above are PUSHING / PULLING/ PUSHING AND PULLING forces.
2. The forces shown above are WORKING TOGETHER / OPPOSITE FORCES.
3. The forces are EQUAL / NOT EQUAL.
4. The forces DO / DO NOT balance each other.
5. There IS / IS NO motion.
6. The net force is __________________ in _________________ (direction).
Two children are moving their wagon across the street. One is pulling the wagon to the
left with a force of 100N and the other is pushing the wagon with a force of 100 N to the
left. Use the picture below to answer the questions that follow.
1.The forces shown above are PUSHING / PULLING/ PUSHING AND PULLING forces.
2. The forces shown above are WORKING TOGETHER / OPPOSITE FORCES.
3. The forces are EQUAL / NOT EQUAL.
4. The forces DO / DO NOT balance each other.
5. There IS / IS NO motion.
6. The net force is __________________ in _________________ (direction).
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