PHS S1

For how many years did people know that when they rubbed certain materials together, they could pick up light items?

for millennia

The force making rubbed items sticked together was first called what?

electric force

Who dubbed the rubbed force "electric force” in 1600?

Philosopher William Gilbert (1544-1603)

What did Gilbert experiment with?

amber

What is the Greek word for amber?

elektron

What did the electric force phenomena require to know the underlying cause?

an understanding of the fundamental properties of matter

In Western thought for centuries, the Earth was made up of a combination of what 4 elements?

earth, air, fire, and water

What does it mean in philosophy when an element is fundamental?

an element cannot be made of anything because everything is made from it

Are the elements on the periodic table today fundamental?

No, they are made of even smaller pieces

Elements on the periodic table are made up of what?

atoms

What does atom mean in Greek?

indivisible

What are 2 arguments about atoms between philosophers?

1.) you can’t divide it in half 2.) you can divide it in half forever

Who is a very famous founding father who never ran for president?

Benjamin Franklin (1706-90)

What did Franklin do for the U.S. and Europe?

helped drafted the Declaration of Independence and helped France against England

How did Franklin become popular in France before his involvement in politics?

his activities

Franklin read about a popular invention in Europe called what?

Leyden jar

What is a Leyden jar?

device that stores electricity and delivers an electric shock to anyone who touches it

How did Franklin become interested in building his own devices?

the electric properties of the Leyden jar

What did Franklin call Gilbert’s “electric force?”

electrical fire

What did Franklin find about electrical fire?

not only could it attract, but it could also repel things

What did Franklin decide about certain objects regarding electrical fire?

some tended to pick it up, while some tended to lose it

What was Franklin’s very important discovery?

electric charge is conserved, moved between objects

Franklin is best known for which electrical experiments?

kites and thunderstorms

What is an incorrect popular depiction of Franklin’s kite experiment?

he stood out in a thunderstorm holding a key attached to a kite

What happened when some reckless people attempted the incorrect kite experiment?

they died

How was Franklin’s kite and thunder experiments actually performed?

he attached a key to a stand surrounded by a smaller shelter, then measured the static electricity buildup on the key from the thunderstorm

Why was Franklin’s kite and thunder experiments significant?

it proved lighting was an electrical phenomenon

What is actually “electrical fire?”

ions moving from atom to atom

In physics, what is a particle?

a fundamental piece of matter of which everything else is made

Atoms are composed of how many times of particles?

3

How are protons and neutrons similar aside from being in the nucleus?

similar mass

What is mass?

A fundamental quantity of nature, measured in kilograms, which determines an object’s response to forces

What is the mass of one liter of water?

one kilogram

A typical adult human has a mass of what kg?

60 to 70

Mass is also sometimes referred to in terms of what?

inertia, resistance to changes in motion

Who painted “Benjamin Franklin Drawing Electricity from the Sky,” a depiction of his kite experiment?

Benjamin West (1816)

Most atoms have an equal number of what?

protons and electrons

Oxygen is no. what? and has how many protons and electrons?

8

An element is defined by its number of what?

protons

Electricity primarily involves the movement of what?

electrons

Which particle in the atom plays no role at all in electricity?

neurons

Is electric charge a fundamental quantity of particles?

yes

What are the electrical charges of protons and electrons?

opposite and equal

What keeps electrons in orbit around the protons in the nucleus?

the attraction to each other

What does Newton’s first law of motion say?

an object’s inertia will allow it to keep going as long as there is no forces stopping it

The strength of a force is measured in what?

newtons

How much is the weight of an apple?

One newton

What does the term “forces” refer to?

interactions between objects and ways in which one can change the motion of another

What does Newton’s second law of motion say?

an object feeling a force will accelerate in the direction of that force (F=ma)

More force means more what?

acceleration (F=ma)

What does Newton’s third law of motion say?

Every action has an equivalent reaction

Why do the Earth and Sun not accelerate toward each other equally despite exerting the same gravitational force towards each other (N3L)?

From N2L, Earth has a much lesser mass, so it accelerates due to force of gravity much more than Sun, whose acceleration is near negligible compared to Earth.

A proton has over how many times the mass of an electron?

a thousand

Why do protons and electrons not accelerate towards each other equally?

protons are way heavier

Are protons and neutrons truly fundamental?

No, they’re made up of quarks

Science involves building models that approximate what?

reality

In most cases, why do we model protons as a fundamental particle even though it’s not?

Our model will still match up with reality

Are electrons truly fundamental?

As far as we know

What is the mass of the Sun in kg?

2×10^(30)

What is the mass of a single proton?

1×10^(-27)

kilo (k) power of 10?

10^3

mega (M) power of 10?

10^6

centi (c) power of 10?

10^(-2)

milli (m) power of 10?

10^(-3)

micro (μ) power of 10?

10^(-6)

nano (n) power of 10?

10^(-9)

How many fundamental forces are in the universe?

4

What are the 4 fundamental forces?

force of electricity attracting and repelling ions, strong nuclear force keeping protons and neutrons together, weak nuclear force transforming particles into other particles, and gravity

Which fundamental force is primarily involved in radioactive decay?

weak nuclear force

Gravity is a force that does what?

pulls mass towards other mass

What does the strength of the gravitational force depend on?

the masses of the 2 objects and their distance apart

What is the equation for the gravitational force?

Fg=Gm1m2/r²

What are the two ms in the gravitational force equation?

The masses of the 2 objects exerting the force on each other

What is the r in the gravitational force equation?

The distance between the two masses

What is the inverse square law?

describes an equation that solves for a quantity that is inversely proportional to the distance squared

Aside from Fg, what’s an example of the inverse square law?

brightness of an object

Jupiter is x5 further away from the Sun than Earth, and due to the inverse square law, how much sunlight does it receive compared to Earth?

1/25th

What is G in the gravitational force equation?

gravitational constant, or Newton’s constant

What is the numerical value of G in the gravitational force equation?

6.67×10^(-11) Nm²/kg²

What is the mass of the Earth?

6×10^(24) kg

Why can’t we feel the Fg of objects near us?

The G constant is so small the Fg is essentially 0

What is a proton’s mass?

1.7×10^(-27) kg

What is an electron’s mass?

9.1 ×10^(-31) kg

What is the fundamental force of electricity calculated with?

Coulomb’s law

What is Coulomb’s law?

Fe=kq1q2/r²

When did Charles Coulomb discover his equation?

1785

How did Coulomb figure out his equation?

He used a torsion balance in which a charged rod is suspended by a string and can be twisted by the slight electric forces created by the charge

What does q1 and q1 represent in Coulomb’s law?

the amt of charge on the two objects measured in coulombs

What is k in Coulomb’s law?

Coulomb’s constant

Coulombs are defined in terms of electric current in what scaled devices?

human-scale

T/F One Coulomb is huge compared to the charge of a proton and electron

True

What are the charges of protons and electrons?

+-1.7×10^-19 coulombs

What is the smallest charge anything can have?

an electron’s charge b/c it is fundamental w/ -1.7×10^-19

Charge is quantized, meaning…?

it comes in discrete, countable amounts

When we talk abt an object being charged w/ static electricity, what charge units do we use?

micro or nanocoulombs

Why is the fundamental charge and mass and size of particles we measure so tiny?

our human measuring devices are just too big

What are the differences between the fundamental forces of gravity and electricity?

electricity can be attractive or repulsive, gravity is only attractive. The k constant in Coulomb is much greater than G in gravity

What is the k constant in Coulomb’s law?

8.99×10^9 Nm²/C²

How much is electric force stronger than gravity?

a factor of more than 10^40

If electrical force is stronger than gravity, why don’t we notice it in every day life?

Most atoms are electrically neutral because the total charge of the entire atom is 0