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Level 57

## Ignore words

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air resistance
Fluid friction acting on an object moving through the air.
duration
Length of time something lasts
force
(interactions between two objects)
free fall
a state in which an object is gravitationally drawn to the earth's surface and is unaffected by any forces besides weight
friction
a contact force; type of force between two touching surfaces
frictionless
lacking all friction
Gravitational Field Strength
gravitational force per unit mass experienced by a mass placed at that point
kilogram
SI unit used in energy equations to measure mass
normal force
a perpendicular contact force exerted by a surface on another object is a(n) _______.
resistance
a force upon an object that slows down motion
static
Having no motion or change
stationary
In rolling without slipping, the bottom of a rim rolling on the ground is . . .
elliptical
An orbit shaped like an oval, not a circle
A straight line from the center to the circumference of a circle or sphere.
Acceleration of a Particle Moving at a Constant Speed in a Circle
The velocity of the object going around the circle is constant. However, the object is still accelerating because the object is continuously changing its direction (velocity changes, speed doesn't).
centripetal acceleration
a = centripetal acceleration
Centripetal Force
A force directed towards the center of a circle that causes an object to follow a circular path
Tangential velocity
A velocity parallel to the Earth's surface
Force due to gravity
Force responsible for Moon's Orbit
Uniform circular motion is motion of....
an object traveling on a circular path at a constant speed
magnitude at all points in the circle
Uniform circular motion: since the speed is constant, vectors have the same....
is NOT constant
the direction of the vector in uniform circular motion...
an object in uniform circular motion accelerates toward....
the center at all times during the motion
the centripetal acceleration vector always points toward...
the center, and continually changes direction as the object moves
the centripetal force always points toward the....
center of the circle and continually changes direction as the object moves
the center of the circular path
the centripetal force is merely the net force pointing toward...
the net force (centripetal force) is the vector sum of...
all the force components that point along the radial direction
tension, friction, gravitational, normal force
sometimes the centripetal force consists of a single force such as...
when a car travels around a banked curve, what holds the car down?
static frictional force between the road and tires that create the centripetal force
the curve is banked at a an angle relative to the horizontal
the reliance on friction can be completely thrown away for a given speed, if....
normal force (Fn) provided by road
the forces acting on a car during a banked turn .....
1 speed:
there is only _______ speed that a satellite can have if it is to remain in fixed orbit
Uniform Circular motion
A particle moves in a circle with a constant speed
Velocity
a speed in a particular direction.
Does an object in uniform circular motion have constant velocity?
No it does not. Because velocity is speed and direction and direction is constantly changing in a circle, therefore there is no constant velocity
acceleration
(physics) a rate of change of velocity
If an object is moving in UCM does it have a constant acceleration?
No it does not because acceleration is the change in velocity and velocity is speed and direction, and direction in UCM is always changing, therefore acceleration cannot be constant
What is centrifugal force?
Centrifugal means fleeing from center however it is a fake force and is just an extension of newton's 1st law
What does centripetal force mean
Center seeking and it does exist
Towards the center
Acceleration in these problems always points where?
Time for one revolution (so time/revolution)
What does period ( fancy T) mean
1/2= .5 so .5
Let's say an object makes 2 revolutions in 1 second...what's T
mg
expression for the weight of an object
The object would go off in a linear path in the direction of the velocity at that instance
If a centripetal force ceased to act on an object moving in a circular path what happens to the object?
static friction
A car drives with its tires rolling freely. Is the friction between the tires and the road kinetic or static?
It increases
As an object speeds up what happens to the centripetal force?
What did Brahe do?
Collected 30 years worth of data on planetary motion and did nothing with it
What did Kepler do?
He inherited Brahe's data and came up with the three laws of planetary motion
What did Newton do to circular motion and gravitation
He discovered the law of gravitation (everything is attracted to everything else)
What did Cavendish do?
He determined the value of universal gravitation (G)
What is kepler's first law of planetary motion
Planets orbit elliptically and the sun is at one of the foci of the ellipse
What is kepler's second law of planetary motion?
Planets sweep out equal areas in equal times
What's kepler's 3rd law of motion?
Period is related to the 3/2 power of the radius
Whats a planet's perihelion
When is closest to the sun in its orbit
What's a planet's aphelion?
When it's furthest from the sun on its orbit
Faster at perihelion, slower at aphelion
When is a planet moving faster? Aphelion or perihelion?
Why is a planet moving faster at the perihelion?
The planet is closer to the sun's gravitational pull
No. Remembers newton's 3rd law, for every action there is an equal and opposite reaction therefore they are equal
Does the earth attract the moon more just because the earth is larger than the moon? ( this applies to all objects)
Does one escape the earth's gravity if you're on the moon?
Nope! Newton's law of gravitation states that everything in the universe is attracted to every other thing
Describe the cannon shot thing
If you shoot the cannon ball to weak it'll crash down into earth, if you shoot it hard enough it will enter into satellite orbit around the earth. If you shoot it too hard i…
Something that orbits
What does satellite mean?
The same as earth, 24 hours
What is the period of a geosynchronous satellite?
What does geosynchronous mean?
In synch with the earth
Above the equator
Where does a geosynchronous satellite need to be?
Yes they do. Idk why
Are all geosynchronous satellites need to be at the same height?
For an equation dealing with the rotating amusement park ride how do you draw the fbd?
With a standard coordinate plan, normal force is centripetal, Gravity is down, and static friction is going up