Zusammenfassung der Ressource
Newman Semester 2
- Circular
Motion
Anmerkungen:
- Mrs. Newman Webpage: https://drive.google.com/open?id=0B6uqOOeFiIDvfk1NbWphRk1pbV91VXZ1NUMweWlPMElXNHZTLU5tSHdTVmctOFFhdlU2OTQ&authuser=0
- Centripetal Force
- Fcentripetal = m* v2/r
- Any force can be centripetal
- force that causes an object to move in a circle
- will change directions to always point inward to the center
- inertia is what allows it as it makes the object stay in the motion you put it in
- centripetal force and velocity are perpendicular on a diagram
- If you stop spinning the object in a circle (or string snaps) the object will follow the
velocity
- directly proportional to mass
- inversely proportional to raidus
- directly proportional to the square of the object's linear speed
- Rotation &
Revolution
- Rotation
- Spinning on an internal axis
- Example: a basketball
spinning on a finger
- Revolution
- An object spinning on an external axis
- Example: A merry-go-round
- Distance traveled = circumference
- radius = person distance from center of axis
- C = 2(pi)r
- Linear and Angular Speed
- Linear Speed
- Distance traveled per unit of time
- Those farthest from the center will have the fastest
linear speed
- v = 2(pi)r / t (time for one revolution (seconds) )
- Angular Speed
- Amount an object in circular
motion spins per unit of time
- Angular Speed = Rotations or Degrees / time
- 1 rotation = 360 degrees
- People in different positions will still have same angular speed
- Centrifugal force
- not a true force
- apparent outward force
- effect of inertia when object is being forced into a circle
- Gravitational Force
- Fgravity = G(m1*m2)/r2
- G = 6.67e-11
- Force of gravity between Earth and the sun keeps Earth in its orbit
- exists between all objects that have mass
- Strength of force depends on the mass of the
objects and the distance between them
- weight = force of gravity between you and Earth
- depends on your mass, your planets mass, and distance from center of planet
- force of gravity b/w two objects lies along the line connecting their centers
- direction of the force changes to stay pointed along the line b/w their centers
- mass and gravity are directly proportional to each other
- distance and gravity are inversely squared
- decrease of graviational force is related to the square of the distance
- double the distance = force divided by four
- measured from center of both objects
- Work, Power, Energy
Anmerkungen:
- Unit Folder: https://drive.google.com/a/student.dist113.org/folderview?id=0B6uqOOeFiIDvfm41dE9CbFEzODExeVZTaVhBZ1lQX1R3VzZib0VLTGJ5TFpXUFR5UzU1RUU&usp=drive_web
- Work (Done Against Gravity
- W= mass*gravity*height
- work done by or against Fgravity
- force times the distance moved in the direction of the force
- total work done against gravity same no matter the path
- W = F*d
- Fg = m*g
- measured in Joules or Newtons (depends on problem)
- Power
- rate at which work is done
- measured in Watts
- 1 watt = 1 joule per second
- Sometimes horsepower is used
- One hP = 746 Watts
- P = work/time
- Energy
- Potential Energy
- Energy due to its position
- gravitational potential energy
- energy of an elevated object
- Ep = m (mass kg)* g (acceleration due to gravity, 9.8/10 m/sec2) * h (height meters)
- Kinetic Energy
- Energy of motion
- Ek = 1/2 *v * v2
- direct relationship with mass
- directly squared of velocity
- Ep top = Ek bottom
- Never created or destroyed; but converted into other forms
- Electricity
- Waves
- Sound
- Light Color And Optics