1. Unit for power
   Unit for force
2. Unit for pressure
   Unit for weight

In general, watts refer to how much power is in an electrical circuit. If you're ever out buying light bulbs, you will see the wattage of bulbs can be different. This shows how much light the bulb can produce, if put in a proper socket.

1. Microwaves
   Inertia
2. The window resisted the break.
   The ball doesn't abide by the rules of physics.

Inertia is an object's ability to resist change based on the composition of an object. This means that the ball didn't change momentum as it crashed through the glass because it was denser than the glass itself.

1. Sea fall
   Free fall
2. Gravitational fall
   Marker fall

When someone or something is in a free fall, there is no other force affecting their speed or acceleration than gravity. For example, a skydiver simply falls from the plane and allows gravity to help them accelerate.

1. Anticlimactic
   Thermal equilibrium
2. Unusable data
   Microtransfer

Thermal equilibrium is a term used for two different objects that are of the same temperature. There is no heat transfer between them because neither is taking heat or releasing heat.

1. Enhancement
   Magnification
2. Microfication
   Telescopic ratio

There are times when science has a tendency to make things a little more complicated than they have to be. Physics is no different. Magnification is when the image of something is a different size than the actually object.

1. Nuclear fission
   Nuclear fusion
2. Nucleo-adherence
   Nuclear meltdown

When nuclear fusion occurs, you will also see a reaction in the form of a release or absorption of energy. Nuclear fusion requires extremely high temperatures to actually happen.

1. They have floating legs.
   They don't really land on the water.
2. Microabrasian
   Surface tension

Surface tension isn't exclusive to water. As a matter of fact, nearly every liquid has some amount of surface tension. This property of liquids functions very much like a membrane over it, adding resistance.

1. Humans can't hear it.
   It annoys humans.
2. It disrupts human hearing.
   It injures human hearing.

Infrasonic sound waves at a frequency so low that it cannot be heard by human ears. This frequency has to be less than 20Hz. However, if the pressure is high enough, humans can still perceive it.

1. Radio series
   Podcast series
2. Spectral series
   Book series

The hydrogen atom is rather unique. The Lyman series refers to a group of lines (or a spectral series) within the ultraviolet region on the hydrogen spectrum. It is created when electrons move from one energy level to another within the atom.

1. The amount of mass that is lost after 50 years
   The pressure that is needed to disintegrate half of the atoms in an element
2. The amount of time it takes for half of the atoms in an element to disintegrate
   The outside forces that disintegrate an atom

A half-life also refers to the time it takes for the radioactivity of an isotope to be cut in half. Many elements have half-lifes that are much longer than you'd think. For example, Plutonium 239's half-life is over 24,000 years.

1. Height
   Weight
2. Mass
   Milligrams

While many people think of weight as how heavy something is, in physics terms, weight actually refers to force. You can figure out the weight of something by multiplying mass by gravity.

1. Pressure
   Time multiplied by speed
2. Light
   A back and forth motion

Sound waves create vibrations. These vibrations are actually just a consistent motion that repeats itself, moving back and forth. The oscillations come from an equilibrium point and fan outward.

1. Pressure multiplied by force
   Heat multiplied by pressure
2. Force multiplied by displacement
   A unit of measurement for mass

While many believe that work is something that you show up to every day, the true definition of work requires something to move or function. You can push on a brick wall until you're sweating, but if that wall doesn't move, you're not doing any work.

1. An open system
   A closed system
2. An electrical system
   The Fornum system

There are open systems and closed systems. In open systems, mass and energy can be lost or gained from the environment alone. On the other hand, closed systems don't interact with their environments.

1. Expose it to heat
   Expose it to water
2. Expose it to cold
   Expose it to a magnet

A spectral line is a dark or bright line that occurs in a uniform spectrum. When you place a magnet to this spectrum, you can see the line begin to spit off. This is the Zeeman effect.

1. Sprain
   Strain
2. Mass
   Width

When it comes to elasticity, Hooke's law explains what is needed to expand or contract a spring. The law states that stress and strain applied to an object must be proportional to achieve a goal.

1. The temperature ice cracks under atmospheric pressure
   The pressure used to create ice without changing temperature
2. The mass of ice before it stops floating
   The temperature ice melts based on regular atmospheric pressure

The ice-point and the melting-point of ice are the same thing. It seems odd to call a melting-point an ice-point, but the temperature is consistent. It is either 32 degrees F or 0 degrees C.

1. 100 degrees F
   212 degrees F
2. 50 degrees F
   32 degrees F

A steam-point doesn't necessarily refer to the temperature of the water itself. It actually is more specific to the steam above boiling water. In any case, at sea level, the steam-point of water is 212 degrees F.

1. Interthermal process
   Semi-thermal process
2. Anti-thermal process
   Isothermal process

An isothermal process is necessary for creating reactions at slower speeds. They usually happen when the system (or the thing being changed) is changed very slowly with the help of a thermal reservoir or a heat bath.

1. 19,254 Hz
   17,201 Hz
2. 21,574 Hz
   4,748 Hz

Ultra sonic sound is any sound wave that has a frequency that is higher than a human's ability to hear it properly. That means any frequency over 20,000 Hz is considered ultrasonic.

1. Rest state
   Fall state
2. Microstate
   Ground state

The ground state of an atom is also called the zero-point energy of the system. The opposite of the ground state is known as the excited state, which is an a state that is anything above the ground state.

1. The amount of light that creates heat from a source
   The amount of time it takes for light to become visible
2. The distance light is able to travel from a stationary source
   The amount of energy radiated from a source per second

In physics, luminosity doesn't necessarily have to refer to light. It can refer to energy that isn't visible as well. It mostly refers to the amount of radiation that is emitted from a single source.

1. Sound wave
   Water wave
2. Light wave
   Jump rope wave

The only item on this list that is not a mechanical wave is a light wave. Light waves are considered electromagnetic waves because they can travel through a vacuum (like space), whereas mechanical waves cannot.

1. Megaconductor
   Ultraconductor
2. Superconductor
   Insulation

When it comes to the way electricity moves, nearly everything gives a little resistance. However, there are some materials that will reduce the resistance almost to zero under the right conditions.

1. Kepler's first law of planetary motion
   Kepler's second law of planetary motion
2. Newton's fourth law of gravity
   Lenz's law

In the 1600s, Kepler created three laws of planetary motion based on his observations of the stars. Each of these laws still holds up today based on our reviews of how the planets move and interact with other celestial bodies.

1. G = MC^2
   M = GHB
2. PV = nRT
   Y=N^6

The ideal gas equation describes the state of a hypothetical gas (or ideal gas). The P, V and T stand for pressure, volume and absolute temperature. The n represents moles of gas while R stands for the constant of the ideal gas.

1. Size
   Composition
2. Shape
   Air resistance

To properly record the natural frequency of an oscillating object, you have to first ensure that there are no external forces affecting it. This will help you understand how the object moves without outside factors.

1. Kelvin's law of heating
   Relative mass
2. Joule's law of heating
   Kinetic energy

Joule's law of heating defines the heat that is produced by an object. In this equation, the I stands for the current flowing through a resistor (represented by the r) over a given time (t). Q represents the heat that is produced.

1. An object in motion will stay in motion until an outside force stops it.
   There is no third law of motion.
2. Every action has an equal and opposite reaction.
   The gravitational attraction of two particles is proportional to their mass.

There are three laws of motion, according to Newton. While you might not be able to see the fact that every action has an equal and opposite reaction (because it can be subtle sometimes), this law has yet to be disproved.

1. Spin quantum number
   Spinnerette
2. Quantum angle number
   Tilt axis number

The energy state of electron waves have four different descriptions. Of these four descriptions, the spin quantum number represents the orientation as it relates to an outside magnetic field.

1. Fundamental frequency
   Ground frequency
2. Low frequency
   No frequency

For those who study frequencies, the fundamental frequency is referred to as the fundamental. It is the lowest possible frequency of a wave form. For example, in music, it is the lowest pitch of a note.

1. Five
   There isn't enough information to answer this question.
2. Six
   Nine

In order to figure out the mass number of a nucleus, you have to first know how many protons and neutrons it has. If you know these two numbers, simply add them together and you have the mass number.

1. The amount of outside heat added to something to raise its temperature by one degree
   The amount of heat something can hold
2. The amount of heat a solid can withstand before turning into a liquid
   The amount of heat something releases.

When you consider the definition of thermal capacity, it's important to note that the entire object or body needs to raise by one degree before the proper capacity can be calculated.

1. The latent heat of vaporization
   The despondent heat of vaporization
2. The vapor point
   The Kelvin code

The latent heat of vaporization refers to the amount of heat that is needed to convert a specified amount of liquid into its gaseous form. Here's the catch: when you're looking for the latent heat of vaporization, you can't change the temperature of the liquid. You simply have to add energy.

1. 746
   521
2. 198
   Horsepower is not measured in watts

Both a watt and a unit of horsepower are units that measure power. One H.P. (horsepower) is equivalent to 746 watts. Horsepower is used to describe the rate that mechanical energy is expended.