Here are a few important Physics definitions that you may want to know:
Acceleration: An increase in speed. To accelerate means to go faster. Physicists define acceleration as a measure of the rate of change of velocity over time.
Acoustics: The study of how sound behaves, usually in rooms, halls, and auditoriums. The volume, quality, and amount of reverberation of sound are often important acoustic characteristics about a room.
Assumption: When experimenting, scientists often make assumptions that certain things are true. An assumption is something that is believed to be true
Buoyancy: The buoyancy of an object is its ability to float on the surface of water (or any fluid). Water gives an upward push on any object in it. The amount of force pushing up is equal to the weight of the water that the object “displaces” (takes the place of).
Calibrate: To make a correction or adjustment, often a measuring device. When two thermometers are being used in an experiment, it is important that both are reporting temperatures accurately. When they are in the same place, they should both read the same temperature. If one is reading higher than the other, it must be noted and the difference in temperature must be added or subtracted from the other one in all experiments where the temperatures on the two thermometers are being compared.
Centrifugal force: A force that pushed outward when an object is moving in a curve.
Conductor: A material that makes an easy path. Metal is a good conductor of heat, making an easy path for heat to be carried along.
Diameter: The distance across and object measured as of a straight line was drawn from one side to the other through the middle.
Echo: A distinct repeat of sound. If the ear heard two sounds that are the same but the second sound is at least 65 milliseconds later than the first sound, the brain will interpret them as an echo or as separate sounds. An echo is caused by sound reflecting off a surface and returning back to the ear.
Elasticity: The material’s ability to be stretched or compressed and then return to shape.
Force: A push or pull on an object. It is an action that can change the motion of a body. Sources of a force include gravity, electricity, magnetism, and friction.
Frequency: Referring to radio waves, the “frequency” of an electromagnetic wave is the number of times it “vibrates,” or “cycles,” per second.
Friction: Friction is the resistance to motion when two things rub together. Friction keeps a car on the road. It makes your hands warm when you rub them together quickly. Melting ice reduces friction, which makes it hard to walk on it without falling.
Fulcrum: The supporting object around which a lever (a simple machine) pivots.
Gravity: A force of attraction between two objects.
Heat sink: Usually a specially shaped piece of metal used to carry heat away from an object. In electronics, heat sinks are attached and integrated circuits to keep them cooler.
Hydraulics: A branch of physics that studies the laws of liquids in motion.
Hypothesis: A thoughtful, reasoned guess about something, based on what is known. A hypothesis must be proven by experimentation.
Incandescent Bulbs: Most home lighting comes from incandescent or fluorescent bulbs turning electrical energy into light energy. In and incandescent bulb, electricity passes through a small wire, called a filament, which glows brightly. In a fluorescent bulb (a long, straight, or circular tube), the inner surface is coated with materials called phosphors and the tube is filled with a gas. When electricity passes through the bulb’s heating element, the gas gives off rays that cause the phosphors to fluoresce (glow).
Kinetic Energy: The energy of work being done; the energy of motion. A bowling ball rolling down an alley is an example of kinetic energy. See potential energy.
Magnetism: A force exhibited by certain objects that attract iron.
Mass: The amount of “stuff” of which an object is made. The more mass it has, the heavier it is. A ping pong ball and a golf ball are about the same size and shape, but a golf ball has more mass.
Microwaves: Microwaves are a kind of radio frequency energy. They are electromagnetic waves. Their frequency (the number of times the wave vibrates each second) is much higher than most other types of radio and TV waves. Microwaves are used for telephone and satellite communications as well as for cooking in “microwave ovens.”
Observation: Using your sense – smelling, touching, looking, listening, and tasting – to study something closely, sometimes over a long period of time.
Pendulum: A weight hung by a wire or string tied to a fixed point (one that doesn’t move) is called a pendulum. If the weight is pulled to one side and then released to fall freely, it will swing back and forth. Gravity pills it down, and then momentum keeps it moving past the “At rest” hanging point. Eventually, the weight stops swinging back and forth because air friction slows it down.
Potential Energy: Stored-up energy; ability to do work. A rock resting on a hilltop has potential energy’ the ability to do work because of gravity. See kinetic energy.
Power: Power is defined as the rate of doing work or energy used. Power equals work divided by time. Units of measure of power are the watt and horsepower.
Quantify: To measure an amount of “how much” of something.
Radio frequency energy: Electromagnetic waves used to carry TV and radio signals.
Reverberation: The sound of thousands of echoes washing together, each echo having a different delay. The ear doesn’t hear any one particular echo, but rather a mixture of indistinguishable sounds.
Simple Machines: Tools – such as levers, inclined planes, pulleys, wedges, screws, and wheel and axles – that make it easier to do work. All complex mechanical machines are made up of Simple Machines. Simple Machines provide a way to change a force to a distance, a distance to a force, or to change direction ( a pulley on a flagpole changes the downward force on a rope to an opposite, upward, movement of a flag).
Surface Area: The amount of outside area of an object.
Tare weight: The tare weight is the weight subtracted from a gross weight to allow for the weight of the container. The result gives the weight of the contents of the container or holder. If you want to know how much your cat weighs, but he still won’t sit still on a scale, weight yourself holding the cat. Then weight just yourself. Subtract your weight (the tare height) from the weight of both you and the cat. The answer is the cat’s weight.
Tensile strength: How strong something is, and how much tension or pressure it can take before it breaks. Steel has great tensile strength.
Torque: A twisting force, or the force used to rotate an object.
Trajectory: The path of an object as it travels through the air.
Unbalanced force: A push of pull on an object that is stronger in one direction than any push or pull in the opposite direction.
Velocity: Speed with a direction of the motion assigned to it.
Wavelength: A wave is a form of energy travel, like rolling waves in the ocean. Sound and radio waves would look similar to ocean waves, if we could see them. A wave has a “crest” or peak (highest part) and a trough (lowest part). The length from crest to crest or trough to trough is he “wavelength.” The wavelength of a tsunami ( a tidal wave) can be 100 miles (161 kilometers) long!
Weight: The force of gravity pulling downward on an object, toward the Earth.
Work: The measure of motion-producing effects of a force. The formula in Physics for work is WORK = FORCE x DISTANCE.