Science: All Vocab

Motion

When an object changes position

Relative Motion

Occurs relative to your environment

Distance

How far an object moves

Displacement

The distance and direction of an object’s change in position from a starting point

Speed

The distance an object travels per unit of time

Average Speed

The total distance traveled divided by the total time traveled

Instantaneous Speed

The sped given at one particular point in time

Velocity

Includes the speed of an object and the direction of the objects motion

Acceleration

The rate of change in velocity

Force

A push or a pull that one object exerts on another

Balanced Forces

Equal forces in opposite directions that result in a zero net force

Net Force

The result of all forces acting on an object

Unbalanced Forces

A force on an object that is not balanced by another force - can result in the motion of the object

Inertia

The tendency of an object to resist a change in motion

Gravity

The attractive force exerted by any two objects

Air resistance

A force that acts in the opposite direction of the object’s motion

Terminal Velocity

The highest acceleration an item in free fall will reach, when forces of air resistance and gravitational pull are balanced, resulting in a net force of zero

Newton’s first law

An object in motion will stay in motion unless acted upon by an unbalanced force

Newton’s second law

An object will accelerate in the direction of the net (unbalanced) force

Newton’s third law

For every action, there is an equal and opposite reaction

Friction

The force that opposes the motion between two surfaces touching one another

Fluid friction

A force of friction between an object moving through a fluid (air or water)

Static friction

The friction between two surfaces that are not moving past each other - usually the greatest due to frictional forces

Sliding Friction

the force that opposes the motion of two surfaces sliding past eachother

Rolling Friction

The friction between a rolling object and the surface it rolls on - usually the least due to little surface area to allow static interlocking

Centripetal Force

A force directed towards the center of the circle for an object moving in a circular path

Momentum

A property of an object that is related to how much force is necessary to change it’s motion

Law of conservation of momentum

Momentum can be transferred from one object to another, it can not be created nor destroyed.

Impulse momentum theorem

Force(time) = mass(change in velocity)

Energy

The ability to do work or cause change

Kinetic Energy

Energy that is in the form of motion

Potential energy

Stored energy

Elastic PE

Energy in something that can stretch or compress, like a rubber band or spring

Chemical PE

Potential energy in chemical bonds

Gravitational PE

Energy in objects that are above the earth’s surface

Law of conservation of energy

Energy can not be created nor destroyed, it simply changes from one form to another

Work

When a force is exerted on an object and the object moves in the direction of that force

Power

The amount of work done in a certain amount of time (the rate at which work is done)

Fission

Splitting a nucleus into two or more smaller nuclei, takes place on earth and in the sun

Fusion

Smaller atoms are compressed into larger atoms, takes place on the sun

Chain reaction

Self-propagating reaction (once it starts, it keeps itself going)

Critical mass

The mass required to sustain a chain reaction

Waves

rhythmic disturbances that carry energy through matter or space

Medium

Material through which a wave transfers energy

Frequency

Number of waves passing in a point of one second

Speed in a vaccum

300,000 km/s