Section 2
-
Upload
dan -
Category
Technology
-
view
422 -
download
0
Transcript of Section 2
Friction and Gravity
Friction
A Smooth Surface? If you look at the polished surface of an aluminum alloy under a powerful microscope, you’ll find that it is actually quite rough.
FrictionThe force that two surfaces exert on each other when they rub together
A Smooth Surface? If you look at the polished surface of an aluminum alloy under a powerful microscope, you’ll find that it is actually quite rough.
FrictionThe force that two surfaces exert on each other when they rub together
The strength of the force of friction depends on 2 things
how hard the surfaces push together
the types of surfaces involved
A Smooth Surface? If you look at the polished surface of an aluminum alloy under a powerful microscope, you’ll find that it is actually quite rough.
Types of Friction
Types of FrictionStatic Friction: Friction that acts on objects that are not moving
Types of FrictionStatic Friction: Friction that acts on objects that are not moving
Sliding Friction: Occurs when two solid surfaces slide over eachother
Types of FrictionStatic Friction: Friction that acts on objects that are not moving
Sliding Friction: Occurs when two solid surfaces slide over eachother
Rolling Friction: When object rolls across the surface
Types of FrictionStatic Friction: Friction that acts on objects that are not moving
Sliding Friction: Occurs when two solid surfaces slide over eachother
Rolling Friction: When object rolls across the surface
Fluid Friction: Water, oil, other liquids cause the object to move easily
Static FrictionTo make the sled move, the athlete firsthas to overcome the force of static friction.Static friction acts in theopposite direction to theintended motion.Sliding FrictionOnce the sled is moving, itslides over the floor. Slidingfriction acts between the sledand the floor in the oppositedirection to the sledʼs motion.Rolling FrictionRolling friction occurs whenan object rolls over a surface.For the skateboarder, rollingfriction acts in the directionopposite to the skateboardʼsmotion.Fluid FrictionWhen an object pushes fluidaside, friction occurs. The surfermust overcome the fluid frictionof the water.Static frictionIntended directionof motionSliding frictionDirection of motionFluid frictionDirection of motion Rolling friction
Gravity
GravityStudyJams
GravityStudyJams
Gravity is a force that pulls objects toward each other
GravityStudyJams
Gravity is a force that pulls objects toward each other
Newton realized that Gravity acts everywhere in the universe
GravityStudyJams
Gravity is a force that pulls objects toward each other
Newton realized that Gravity acts everywhere in the universe
The law of Universal gravitational states that the force of gravity acts between all objects in the universe
Gravity Continued
Gravity ContinuedTwo factors affect the gravitational attraction between objects:
Mass
Distance
Gravity ContinuedTwo factors affect the gravitational attraction between objects:
Mass
Distance
Force also depends on the distance between the objects
Gravity ContinuedTwo factors affect the gravitational attraction between objects:
Mass
Distance
Force also depends on the distance between the objects
Mass is the measure of amount of matter, not to be confused with weight
Gravity and Motion
Gravity and MotionFree Fall: When an object is accelerating while its falling
Gravity and MotionFree Fall: When an object is accelerating while its falling
Air Resistance:
Gravity and MotionFree Fall: When an object is accelerating while its falling
Air Resistance:
Terminal Velocity: is reached when the force of air resistance equals the weight of the object
Gravity and MotionFree Fall: When an object is accelerating while its falling
Air Resistance:
Terminal Velocity: is reached when the force of air resistance equals the weight of the object
Projectile Motion: Something thrown horizontally