# IB Physics Review Guide

## 79 terms · Volle's Definitions for Review

### Terminal Speed

the speed at which the acceleration of a falling object is zero because friction balances the weight

### Uniform Circular Motion

Motion at constant speed around a circle with a fixed radius

### Acceleration

(physics) a rate of change of velocity (Vector)

### Displacement

Distance moved in a particular direction. (Vector)

### Velocity

distance travelled per unit time (Vector quantity)

### Speed

distance travelled per unit time (scalar)

### Projectile Motion

the curved path that an object follows when thrown, launched, or otherwise projected near the surface of Earth

### Force

A push or a pull. (N) (Vector)

=mass x gravity

### Net Force

the combination of all forces acting on an object

### Newton's First Law

an object at rest will stay at rest, an object that is moving will stay moving unless disturbed by an unbalanced force.

### Newton's Second Law

The rate of change of momentum of a body is directly proportional to the unbalanced force acting on that body and takes place in the same direction. (F=ma)

### Newton's Third Law

for every action there is an equal and opposite reaction

### Equilibrium

balance of opposing forces

### Impulse

The change in momentum. (Impulse is equal to the Force XdeltaT) (vector)

### Momentum

The product of mass and velocity (kgm/s) (Vector)

### Conservation of Momentum

For a system of isolated bodies the total momentum is always the same.

### Centripetal Force

the inward force on a body moving in a curved path around another body

### Law of Universal Gravitation

the scientific law that states that every object in the universe attracts every other object. The force of attraction is directly proportional to the product of their masses and inversely proportional to the square of their separation. F=GmM/r^2

### Kepler's Third Law

Equating centripetal force and Newton's law of Universal Gravitation we find that the Period squared/separation is a constant proportion. T^2/r^3=4pi^2/GM

### Energy in Orbits

Total energy of an orbiting body is -GMm/2r

### Work

The dot product of Force and Displacement moved in the direction of the force.

### Kinetic Energy

the energy an object has due to its motion. K=mv^2/2

### Potential Energy

the mechanical energy that a body has by virtue of its position. P=mgh

### Elastic Collisions

Momentum and Kinetic Energy are both conserved.

### Inelastic Collisions

Totally Inelastic Collision-after a collision the two bodies stick together.

### Power

is the work done per unit time.

### Efficiency

Useful of work out/energy put in

### Temperature

is a measure of how hot or cold an object is and it is temperature that determines the direction of heat flow.

### Thermal Energy

kinetic energy of a system's constituent particles

### Internal Energy

the sum of the kinetic and potential energies of all particles in the system

### Heat Capacity

the amount of heat needed to raise its temperature by 1 degree celcius. (J/degree Celsius)

### Specific Heat Capacity

amount of heat required to raise the temperature of 1kg of the material by 1 degree Celsius

### Phase Changes

Phase Changes that require energy includes melting, sublimation and vaporization; phase changes that release energy include condensation, deposition and freezing.

### Specific Latent Heat

A material is amount of heat required to change the state of 1kg of the material without change of temperature.

### Ideal Gases

An ideal gas is made up of a large number of perfectly elastic, tiny spheres moving in random motion.

### Assumptions for Ideal Gas Law

1. Perfectly Elastic
2. Molecules are spheres
3. Molecules are identical
4. No forces between the molecules. (Except during collisions)
5. Molecules are small

Force/Area

### Work done on a Gas

When molecules are given energy. Increase in kinetic energy leads to an increase in temperature and pressure.

### Gas does work

When a gas expands, using kinetic energy. The reduction in kinetic energy results in a reduction of temperature.

### First Law of Thermodynamics

the fundamental principle of physics that the total energy of an isolated system is constant despite internal changes

### Thermodynamic Processes

- Adiabatic process: Q = 0

- Isovolumetric (isochoric) process: W = 0

- Isothermal process: ΔU = 0

- Isobaric process: ΔU = W + Q

### P-V Diagram

p-v-T surface projected onto the pressure-specific volume plane

### Entropy

(thermodynamics) a thermodynamic quantity representing the amount of energy in a system that is no longer available for doing mechanical work. S=Q/T

### Simple Harmonic Motion

periodic motion in which the restoring force is proportional to the displacement

### Restoring Force

the force that brings a system back to equilibrium

### Amplitude

The maximum displacement from the equilibrium

### Period

Time taken for one complete cycle

### Frequency

the number of cycles that the pendulum makes per unit time. 1/T=f. Measured in Hz.

### Angular Frequency

found by multiplying the frequency by 2pi. Describes circular motion

### In phase

same displacement in same time

### Out of Phase

Different displacements

### Damping

the reduction in the amplitude of a wave due to the dissipation of wave energy

### Resonance

an increase in amplitude that occurs when an oscillating system is forced to oscillate at a frequency other than the natural frequency

### Travelling Wave

a wave that propagates energy

### transverse wave

a wave that moves the medium in a direction perpendicular to the direction in which the wave travels

### Longitudinal wave

a wave in which the particles of the medium vibrate parallel to the direction of wave motion

### rays

Show the direction of the waves, right angles to the wavefront

### Wave fronts

line joining points that are in phase

### Wavelength

The distance between , the distance (measured in the direction of propagation) between two points in the same phase in consecutive cycles of a wave

### Wavespeed

the product of wavelength and frequency.

### Superposition

the resultant wave of the addition of individual displacements of waves

### Constructive Interference

the interference that occurs when two waves combine to make a wave with a larger amplitude

### Destructive Interference

the crest of one wave overlaps the trough of another and the their individual effect are reduced

### Reflection

the image of something as reflected by a mirror (or other reflective material)

### Refraction

When the wave hits the boundary between the media at an angle, then the wave changes direction.

### Diffraction

when light passes sharp edges or goes through narrow slits the rays are deflected and produce fringes of light and dark bands

### Standing Wave

a wave that appears to stand in one place, even though it is really two waves interfering as they pass through each other

### Doppler Effect

An observed change in the frequency of a wave when the source or observer is moving

### Resolution

The rayleigh criterion puts a limit on the _____ of two points based on the diffraction of light. Two points are _________ if the central max of diffraction of pattern formed of one point coincides with the first minimum of the other.

### Polarization

the phenomenon in which waves of light or other radiation are restricted in direction of vibration

### Electric Charge

the charge obtained by an object when it gains or loses electrons

### Electric Force

the attraction or repulsion between electric charges.

### Electric Field

a region of space where a charged object experiences a force due to its charge.

### Electric Potential

amount of work per unit charge needed to take a small positive test charge from a place of zero potential to the point.

### Electric Field Lines

point in the direction of the electric field vector (away from positive, and towards negative)

### Equipotentials

are like contour lines on a map which trace lines of equal altitude or electrical potential

### Potential Difference

the difference in electrical charge between two points in a circuit expressed in volts

### Current

The flow of charge. (amp) A