Physics - Spring Final Review 2024

Electrical parts in parallel means they have different simultaneous current lines that add to be total current.

Mapping the ocean floor with sonar is the same physics as ultrasound imaging inside a human.

Transformers use two coils with alternating current and magnetic fields to increase or decrease voltage.

The direction and density of E-field lines help determine if source charges are stronger, and if they are + or -.

A heat engine can turn thermal energy into work, like steam engines and gasoline engines.

Energy is the ability to do work (force times distance).

The voltage is how much ENERGY is carried per an amount of charge.

The Earth's magnetic field shield the surface from dangerous particle radiation.

1 Nm = 1 kg m²/s² = 1 joule (J)

The seven types of EM radiation differ in wavelength and frequency, but all move at light speed and have different uses.

The Electrostatic Coulomb Force equation is similar in form to Newton's Universal gravitation equation.

A two second delay between seeing lightning and hearing thunder means the strike was 2/5ths of a mile away.

One coulomb of electric charge per second is called one ampere of current.

3G, 4G, and 5G use digital signals where phone share the same frequencies with compressed data and ingenious encoding.

The reality of space and time are flexible between inertial reference frames.

By measuring the gravitational constant, Henry Cavendish also calculated the mass of the Earth correctly.

A Sonicare toothbrush can be charged by it's base without metal contacts using induction.

The spreading of the Atlantic seafloor recording the changing polarity of the Earth's magnetic field over mill. of yrs.

Everything is made of atoms, and atoms contain positive protons, neutrons, and negative electrons.

The twin paradox is not a paradox bc one twin undergoes more acceleration making the Earth twin much older.

Earthquakes on the ocean floor causes tsunamis.

An "Elastic Collision" is a collision where total kinetic energy is the same before and after collision.

The universe might split into a multiverse of many branches when the quantum probabilities are collapsed to one outcome.

The total amount of work done equals the change in kinetic energy.

Frequency is how many waves/cycles/vibrations per second.

Everything is made of charged particles, but things are usually neutral because number of p balances number of e.

Kinetic energy depends on mass and speed.

Sound wave reflections are called echoes.

All electromagnetic waves are waves in the electric field coupled with a wave in the magnetic field.

Magnetic domains in iron usually are random and cancel each other out.

According to Einstein, mass is really condensed, concentrated energy.

A mass on a spring, and a simple pendulum with small angle amplitudes are examples of simple harmonic motion.

James Clerk Maxwell came up with four equations that explain all classical electricity and magnetism.

When things move fast, 1. time slows, 2. length contracts in the direction of motion, 3. mass increases

A wave is a disturbance that carries energy through matter or space.

A car's key fob uses radio signals to unlock your car door, and thieves can use a "relay" system to steal it.

Gravity can interpreted as a force in classical mechanics, or as a curve in space-time in modern physics (not a force).

AAA, AA, C, and D batteries are all 1.5 volts.

We can use magnetic patterns to store audio, video, and digital information.

Gravity depends on F = Gm1m2/d^2

In any interaction, total momentum is conserved during the interaction.

When a pole vaulter lands, their gravitational and kinetic energies change to thermal energies.

Eratosthenes used shadows and the distance between two cities to find the radius of the spherical Earth.

Every mass attracts every other mass with a gravitational force.

Nikola Tesla invented alternating current, motors, generators, radio control, radio broadcasting, and more.

Electric current is the flow of electric charges (electrons.)

Using AC at high voltage is better when sending electricity long distances because it minimizes loss to heat.

Wavelength is the distance from peak to peak or equivalent points on a continuous wave.

The difficulty in passing an electric current through an object is a measure of the object’s electrical resistance. 

The smallest bones in your body are found in your ear.

Electric current make magnetic fields.

Satellites are constantly falling, in free fall.

Electrons are particles, but sometimes behave like waves.

Before you check, Schrodinger's cat is both alive and dead at the same time.

The "North Magnetic Pole" is really a south pole so a north pointing compass will point towards the north.

Before you open the bunker/box, Schrodinger's cat is 50% dead and 50% alive at the same time.

James Clerk Maxwell basically figured out electricity and magnetism with four laws circa 1870.

When filling a gasoline can, it must be placed on the ground before the pump touches it.

Light waves behave like particles sometimes.

Entropy of the universe will always increase, and this is part of the definition of time.

Some electric motors use permanent magnets that forces on current carrying coils to turn the rotor.

CRT TVs use magnetic fields to aim electron beams at different parts of the screen to draw one frame.

The period of a pendulum only depends on length, not mass.

When you vibrate a charge, a pulse in the electric field travels at the speed of light. This is light.

Electrical parts in series are connected end to end and have the same current through them.

Impulse (force times time) equals the change in momentum (mass times velocity).

Solar thermal power plants use heat from sunlight to make electricity and don't emit any CO2.

Energy is quantized in bundles called photons, and the energy of a photon is based on frequency.

Johaness Kepler, using Tycho Brahe's data, found 3 laws of planetary motion.

The first electronic message sent from North America to Europe was “What hath God wrought”.

On sailing ships with cannons, powder monkeys (boys who carried the gunpowder for cannons) had to be barefoot.

Hooke's Law says that force is proportional to the stretch or compression (displacement) of a spring.

A faraday cage blocks electric fields.

Energy in a spring, or anything that changes shape and wants to restore its shape, is called elastic potential energy.

White light is all the rainbow colors (different frequencies) added together.

Echolocation (for animals) and SONAR (for machines) are the same thing.

A current carrying coil can be an electromagnet.

The height of a wave is called amplitude.

Energy in your body that you use originally came from the sun.

When pumping gas, you should always touch your car before touching the pump.

Power equals work (change in energy) divided by time.

Robert Millikan used oil drops, x-rays, and electric fields to find the charge of the electron.

Firearms and launching systems recoil because of conservation of momentum.

To coast over a hill (which has potential energy), you need a minimum of speed (kinetic energy).

Rockets work in space by changing the momentum of the ship and oppositely changing the momentum of escaping material.

Sound is a longitudinal pressure wave.

Light, which is a wave, is also a particle called a photon.

Hard drives use metal platters with magnetic patterns on them to store information.

Magnets have two equal opposite poles called NORTH and SOUTH.

Fuses and circuit breakers prevent too much current that would cause fires.

The speed of light is always constant in all inertial reference frames.

Capacitors store electric charge and energy.

Stopping a car slowly with hay or with brick walls is both the same change in momentum and therefore the same impulse.

Energy from height in a gravitational field is called gravitational potential energy.

Entropy is the measure of a system's thermal energy per unit temperature that is unavailable for doing useful work.

During the Jedi duel on Mustafar, Anakin Skywalker (Darth Vader) said, "You underestimate my power!"

Cell phones are called cell phones because each hexagonal area on a map is a "cell" with a tower in its center.

Waves can transmit, reflect, be absorbed, diffract, refract, and scatter.

In some situations, like roller coasters or skiing, the sum of kinetic and potential energies is conserved.

A changing magnetic fields induces current.