Level 56
Level 58

#### 66 words 0 ignored

Ready to learn
Ready to review

## Ignore words

Check the boxes below to ignore/unignore words, then click save at the bottom. Ignored words will never appear in any learning session.

**Ignore?**

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

radius

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