Lesson 2 : Gravity and Friciton Flashcards
(20 cards)
What is gravity?
a force of attraction between objects due to their masses
What is mass?
the amount of matter in an object
What is weight?
the measure of the pull of gravity on an object
Mass is _____________, while weight can ___________.
constant, change
What is mass measured in?
grams or kilograms
What is weight measured in?
newtons
Every object exerts a _____________________ pull on another object.
gravitational
Why do tides occur?
the gravity between the moon and Earth
What happens if the mass of a massive object decreases?
the gravitational force decreases
What happens if the mass of a massive object increases?
the gravitational force increases
What happens if the distance between two massive objects increases?
the gravitational force decreases
What happens if the distance between two massive objects decreases?
the gravitational force increases
What is friction?
a contact force that resists motion between two objects
If the surface is smooth,
there will be less friction
If the surface is rough,
there will be more friction
How do you reduce friction?
by adding a lubricant or by replacing the sliding friction by rolling friction
How do you increase friction?
increasing the weight of the object
What is air resistance?
a force that opposes the motion of objects through the air
What is air resistance in other words?
friction between a moving object and the air around the object
What factors affect air resistance?
size, shape, speed, and density
