Friction
What is friction (as defined in our textbook)?
The force that two surfaces exert on each other when they rub against each other.
Mrs. B knocks over her coffee cup. Balanced Force or Unbalanced Force?
Unbalanced
Which has more gravity: Earth or The Moon?
Earth
Objects falling through the air experience fluid friction called what?
What is the highest height that a cat survived a fall from a building?
42 stories.
What are the two causes of friction?
1-How hard the surfaces are pushed together
2- The type of surfaces involved
When all forces are heading in one direction, how do you figure out the net force? Add or Subtract
Add
Why does the Earth have more gravity than the Moon?
An object that is thrown is called a what?
Projectile
The force of gravity on a person or object at the surface of a planet is called what?
Weight
Friction that acts on objects that are not moving is called what?
Static Friction
When two forces are equal and opposite from each other, what is the net force?
Zero
Distance
When the only force acting on an object is gravity, the object is said to be in _______ _______. (Think of the bridge jumping example.)
Free Fall
What did Galileo discover about the Earth as it relates to the sun?
The Earth travels around the sun. The sun does not revolve around the Earth.
Friction that occurs when an object moves through a fluid (i.e. water, oil, or air) is called what?
Fluid Friction
When two forces are acting opposite of each other, how do you find the net force?
Subtract
9.8m/s2
If one ball is given a horizontal push at the same time as another ball is dropped, they will hit the ground at the same time. True or False
True
What scientific mechanism helped Galileo develop the idea for the clock?
Pendulum
Friction that occurs when two solid surfaces slide over each other is called what?
Sliding Friction
What is the downward force that affects all objects?
Gravity
What does the Law of Universal Gravitation state?
The force of gravity acts between all objects in the universe.
When the upward force of air resistance on an object becomes equal to the downward force of gravity on the same object, the force on the object is: balanced or unbalanced?
Balanced
The greatest velocity a falling object reaches is called what?
Terminal Velocity