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all bodies of mass

exert a gravitational pull on other bodies of mass

small masses exert

less gravitational force

large masses exert

more gravitational force

gravitational force decreases

as distance between objects increases

gravitational force increases

as distance between objects decreases

increased mass and decreased distance

result in the greatest gravitational pull

planets and stars

gravity causes the formation of

in orbit

gravity holds all objects of the Solar System

Newton's first law

An object at rest remain and an object in motion remains in motion UNLESS it experiences an unbalanced force. Also called the Law of Inertia.

an object in motion will remain in motion

at a constant velocity, unless acted upon by unbalanced net force

but gravity from the star pulls on its mass

a planet in motion, would stay in motion at a constant velocity

the planet travels in free-fall around the star

if a star pulls on the mass of a planet

in a state of free-fall

all objects in orbit are actually

object in forward motion

with constant velocity and pull of gravity

free-fall around the sun

the combination of constant velocity and pull of gravity results in

but gravity from a planet pulls on its mass

a satellite in motion would maintain forward motion at a constant velocity

star

a planet orbits a

planet

a satellite orbits a

You have mass -->

Youre attracted to everything

inverse square law

a quantity varies with the inverse square of its distance from its source

Attraction depends on

Mass of objects

Strong nuclear force

Four forces of nature

Binds nucleus

Strong nuclear force

Electromagnetic force

Binds atoms into nucleus

Gravitational Force

(physics) the force of attraction between all masses in the universe

What did Newton know?

He did not know the constant G

(Each mass starts equal)

Double 1 mass --> double Fg

Effect of distance on Fg

Double distance --> 1/4 Fg

Henry Cavendish

A British physicist and chemist whose most famous experiment used a torsion bar to determine the value of the universal gravitation constant to determine the weight of the earth

How cavendish found G

Massed flask of mercury...

Longitudinal

A wave in which the vibration of the medium is parallel to, or in the same direction as, the direction in which the wave travels is called a _______

Medial

Through stomach pointing in back and front axis

Not a parabola

Centripetal force vs. radius graph

Transverse

Side to side axis

Lift from air under wings

Airplane banks and makes turn --> centripetal force supplied by

Mass doubled to 2g

Spinning in circular space station --> vt doubled from 1g of Force -->

AU

Astronomical unit

Tyho Brahe

Kepler took over his planetary studies with planetary motion

2nd Law

Acceleration is produced when a force acts on a mass

3rd Law

Every action has and opposite re-action

yes

do all objects emit radiation at any temperature (answer yes or no)

mass

a body of coherent matter, usually of indefinite shape and often of considerable size

Weight - measure of Fg

Quantity that may change with location

Newtons concept of inertia

Without outside force, moving objects continue at constant speed in straight line

force

(interactions between two objects)

Sideways

Tangential velocity that prevents moon from hitting earth

Siting still

Normal weight

Accelerating down

Less weight than usual

Accelerating up

Greater weight than usual

Free Falling

no other forces except gravity are acting on the object

False

(T/F) Tycho Brahe was a Danish astronomer who confirmed Copernicus's theories by making many observations with his telescope.

Rotational giant wheels produce

Artificial gravity --> space habitats in future

Perturbation

Deviation of and orbiting object from its path around center of force caused by another center of force

Earth satellite

Projectile moving fast enough to fall continually around earth

Ellipse

Satellite travels in an

Constant

Speed that does not vary

8 km/s

Speed object must have to orbit earth

No component of Fg along direction if alley

Why is a satellite and bowling ball not effected by gravity?

Segments of ellipses

Parabolic paths of projectiles

Crash into sun

Planet with tangential velocity of 0

Top of mountain, weight is

Less than at gerund level

Gravitational forces

Gravitational field interacts to cause

Field lines show

Direction and acceleration of force field

Earths center

Where is earths gravitational field zero

weight

A force that comes from gravity pulling down on any object with mass

What are the four fundamental forces?

gravitational force, electromagnetic force, strong nuclear force, weak nuclear force

sun on earth, earth on moon

What is an example of gravitational force?

2 ways an electric charge occurs

charged particles at rest or in motion exert electric forces on each other, charged particles in motion produces magnetic forces on each other

weak nuclear force

Force involved in radioactive decay

linear acceleration

An apple falling to the earth is what kind of acceleration?

earth, force

Since it fell to the Earth, the _ exerted a _ on the apple

exert an equal but opposite force on the Earth

Based on Newton's third law, if the earth exerts a force on an apple that is dropped, the apple must...

attractive

Newton concluded that there is a _ force between any two objects

centripetal acceleration

a = centripetal acceleration

it would leave it's orbit in a straight line path

If the moon did not feel an attraction to the earth, what would happen to it?

Yes, they are changing direction

Are objects that are moving in a circle and constantly changing direction accelerating? Why or why not?

Newton's Law of Universal Gravitation

Every particle in the universe attracts every other particle with a force that is directly proportional to the product of the masses and inversely proportional to the square of the distances between their centers

the earth

Since gravity is the weakest of all the 4 fundamental forces, we can only sense its efects when masses like that of _ are involved

no

Does an ideal gas actually exist...?

your weight

The force of attraction between you and the earth is equal to...?

inverse

Force is _ly proportional to the square of the distance

¼ as large

If the distance is doubled, what happens to the force?

1/9 as large

If the distance is tripled, what happens to the force?

the inverse square law

The relationship between force and distance is called...?

they are equal

On planets and other celestial bodies, what is the relationship between Fw and Fg?

g=(Gm2)/r^2

What is the derived formula for acceleration due to gravity?

Tycho Brahe

Johannes Kepler started his astronomy career as an assistant to _______.

Johannes Kepler

A german astronomer who created the three laws of planetary motion

Isaac Newton

A man from England who realized that the planets move around the Sun because of inertia as well as developing the laws of motion and gravity

What are Kepler's Three laws of Planetary Motion?

the paths of planets are ellipses with the center of the sun at one focus, an imaginary line from the sun to a planet sweeps out equal areas in equal amounts of time, rati…

fastest, slowest

Planets move _ when closest to the sun, they move _ when farther away

period

Time per second; time to go around once

What is speed?

Distance traveled divided by the time interval during the motion.

What is velocity?

The speed of an object in a particular direction.

By changing direction

How can an object have a constant speed and a changing velocity?

direction

A point toward something, determined by its orientation and sense.

How is speed calculated

total distance divided by total time

It is a triangle and it means change

what does the delta symbol look like and what does it mean

meters/second or km/hr

What are metric units for speed

what is acceleration

The rate at which velocity changes overtime

m/s squared

what are the metric units for acceleration

what is formula for acceleration

final velocity-starting velocity/time it takes to change velocity

what is a force

A push or a pull

Newton

(kg*m)/(s*s)

Causes a non-moving object to move

What does a net force cause an object to do

inertia

_______ is the property of an object that leads it to resist any change in motion

Define Newton's first law

An object at rest remains at rest and an object in motion remains in motion, in a straight line unless acted upon by an unbalanced force.

Define Friction

A force that opposed motion between two sources that are in contact

Energy of heat

Friction transforms energy of motion into energy of what?

Friction, intertia

To move an object, what forces must a person overcome?

Meters/second

How is speed measured

s=d/t

Speed equation

D=SxT

How do you solve for D in speed?

D/S

How do you solve for T in the equation for speed.

Mass times acceleration

What is the equation for force

Work/time

What is the equation for power?

Change in speed/time

What is the equation for acceleration?

M/s squaredMotion

What is the unit for acceleration?

displacement

A change in position (delta p).

Distance

a path taken and always a positive number

Newtons 1st law of motion (The law of Inertia)

An object at rest will stay at rest and an object in motion will stay in motion in a straight line at a constant speed (velocity) unless an unbalanced force acts upon it.

Force:

an action that has the ability to Change motion

Mass:

- The amount of matter of "stuff" that makes up an object.

Volume:

the measure of the amount of space an object takes up

Weight:

the force due to Gravity on an object

Law of Inertia

Newton's 1st Law is also know as the law of:

F=ma

Force Formula

action-reaction

other name for third law

note:

while most people know what newtons laws say many people do not know what they mean (or simply do not believe what they mean

Newtons Second Law

A law of motion that states that acceleration is equal to force divided by mass.

Newtons Third Law

A law of motion that states that for every action force here is a reaction force equal in strength and opposite in direction.

1st Law

An object at rest stays at rest, an object in motion stays in motion, UNLESS an UNBALANCED force acts upon it.

forces

Something that does work or causes a change

objects

they are stationary when forces are balanced

gravity

(physics) the force of attraction between all masses in the universe

unbalanced forces

forces that cause a change in the motion of an object

friction

a contact force; type of force between two touching surfaces

tension

a force exerted by any segment of a rope or string on an adjoining segment is _______.

support

lift, in the air (planes/birds)

buoyancy

the ability to float

1st type of friction

sliding friction, like ice skating

2nd type of friction

rolling friction, like bowling

3rd and 4th type of friction

Fluid friction (air of liquid) air and water resistance

lubrication

friction can be reduced by:

one newton is equal to:

the force required to accelerate one kilogram of mass at one meter/second/second

note

objects with different masses accelerate to the ground at the same rate, terminal velocity = 9.8 m/s/s

types of foces

gravity, electricity, magnetism, friction

action and reaction forces

are equal, in opposite directions, and happen at the same time

example of friction

when you rub your hands together in the winter and they get warmer

example of the third law

bat hits ball, ball hits bat

What is friction caused by?

-the random, microscopic irregularities of a surface

Kinetic Friction

Friction between moving surfaces

What is kinetic friction?

the friction encountered When surfaces slide against one another with a finit relative speed

the magnitude of the normal force (n)

What is the force of kinetic friction found to be proportional to?

fk = μk(N)

States mathematically, what can this observation be written as?

What is μk known as?

the coefficient of kinetic friction

-none, it is dimensionless

What dimensions does μk have?

is always positive

What are typical values for μk?

high friction

Are high μk values indicative of high friction or low friction?

oppose motion

Does the force of kinetic friction oppose or support motion?

Is fk = μk(N) a vector equation?

-no, because N is perpendicular to the direction of motion

What is the role of static friction?

to keep two surfaces from moving relative to each other

What is it due to?

the microscopic irregularities of surfaces that are in contact

stronger

The bigger an object, the _______ gravitational force it exerts.

Why?

because both person a and B cover the same angle in the same time

any value between zero and Fsmax

What values can the force of static friction have?

Fsmax is proportional to the magnitude of the normal force

What is the relationship between the normal force and the force of static friction?

Fsmax μs(n)

What is the equation that describes this relationship?

What is μs called?

the coefficient of static friction

-in most cases, μs is greater than μk

How do typical values for μs and μk compare?

What does this indicate?

that the force of static friction is greater than the force of kinetic friction

-between 0.01 and 4

What is the range of typical μs values?

What is the relationship between the force of static friction and the area of contact?

the force of static friction is independent of the area of contact between the surfaces

In what direction does the force of static friction work?

-parallel to the surface of contact, and in the direction that opposes relative motion

static friction

A car drives with its tires rolling freely. Is the friction between the tires and the road kinetic or static?

kinetic

Energy of motion

allow a car to stop with static friction rather than kinetic friction

What do antilock braking systems allow, in terms of static and kinetic friction?

braking distance is reduced

As a result, what is the impact on braking distance?

Due to what fact?

the fact that μs is typically greater than μk

What is the tension in a rope at points 1, 2, and 3?

-in the limit of a rope of zero mass, the tension is the same throughout the rope

-9.81

One scale holds a 1 kg weight from the ceiling. The other scale sits in between two strings (and pulleys), and holds a 1 kg weight on either side. The second scale measures the f…

the net force acting on it is zero

What does it mean when an object is said to be in "translational equilibrium"?

the acceleration is zero

From Newton's second law, what does this mean about the object's acceleration?

In two dimensional systems, what does translational equilibrium imply?

-two independent conditions, Fnet x = 0 and Fnet y = 0

-since the bucket is rising with constant speed, it has zero acceleration

Consider a person lifting a bucket of water from a well by pulling down on a rope that passes over a pulley. If the bucket's mass is m, and it is rising with constant s…

tension is less than the tension in the first case

A person hoists a bucket of water from a well and holds the rope, keeping the bucket at rest. A short time later, the person ties the rope to the bucket so that the …

the same

if take off and landing heights of a trajectory of a projectile are the same, then the time from ground to apex should be _______ the time from apex to ground

the tension in the string is less than M2g

Two masses, M1 and M2, are connected by a string that passes over a pulley. Mass M1 slides without friction on a horizontal tabletop, and mass M2 falls vertically downward. Both masses move with cons…

-g/-9.80

When two masses, M1 and M2, are connected by a string that passes over a pulley...what is the acceleration of M2 when M1 = 0?

0/zero!

The acceleration of M1 and M2 when M1 = M2

free fall

a state in which an object is gravitationally drawn to the earth's surface and is unaffected by any forces besides weight

less than

Is the force of gravity for M1 (M1g) greater or less than the force of tension in this instance?

greater than

Is the force of gravity for M2 (M2g) greater or less than the force of tension in this instance?

because #REF! is heavier than #REF!

What is M1g less than the force of tension while M2g is greater than the force of tension?

-Force of static friction will equal 10 N

If you are given N and a value of static friction that equals 5 N, what will be the impact on the force of static friction if N is doubled? (N becomes 2 N) (igno…

it will be twice as hard to move the object

What will the implications be then on how hard it will be to move the object?

Explain why it is impossible to hold up a street light with perfectly horizontal wires?

-neither of the wires has a vertical component, so there is nothing to balance out the gravitational force

What are the two "pulley tricks"?

tension in a freely running massless rope is uniform

What does this mean in terms of the tension?

-if you have two objects, the tension acting on the two objects is the same!

What does this mean in terms of acceleration?

acceleration of the two objects will be equal in magnitude but opposite in direction

size is constant

Describe the size of the force of kinetic friction?

-varies, from 0 to (ms)(N)

Describe the size of the force of static friction?

because it is a good measure of the contact between an object and a surface

Why is N used to calculate the force of static friction and the force of kinetic friction?

As a ratio, what does the coefficient of static friction represent?

the maximum amount of friction force that can be exerted per unit of contact force

how smooth a surface is

What does the coefficient of static friction give you a good gauge of?

Explain why mass has no impact on the force of static friction or kinetic friction

-although having a greater mass means that there is a larger force trying to move an object (mg sin theta), there is also a larger force trying to hold it in place (mg cos theta, N)

Why not?

because each different conservative force has a different expression for potential energy

mg sin theta > force of static friction max

When an object is on an incline and it slides, what is the relationship between mg sin theta and force of static friction max?

the force needed to start a motion is greater than the force needed to maintain a motion

How does the force needed to start a motion compare to the force needed to maintain a motion?

force of static friction max > force of kinetic friction

What does this then imply about the relationship between the force of static friction max and the force of kinetic friction?

the static coefficient is always greater than the kinetic coefficient for the same two surfaces

What does this then imply about the static coefficient and the kinetic coefficient for the same two surfaces?

force of push < force of static friction max

When an object stays at rest, what is the relationship between the force of the push and the force of static friction max?

velocity will not be constant because the object will continually be accelerating

When an object moves, will its velocity be constant? Why or why not?

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Energy, Work, Power