Kinetic Theory, Heat, and Temperature Flashcards

Flashcards on Kinetic Theory, Heat, and Temperature

Kinetic Theory of Matter: Assumption 1

All matter is made from extremely small particles.

Kinetic Theory of Matter: Assumption 2

All particles are in constant, rapid motion (translational, rotational and vibrational).

Kinetic Theory of Matter: Assumption 3

Particles collide with neighboring particles in elastic collisions.

Kinetic Theory of Matter: Assumption 4

Forces of attraction exist between these particles.

Solids (Kinetic Theory)

Particles held in fixed positions and can only vibrate due to strong attractive forces; incompressible.

Liquids (Kinetic Theory)

Particles can move more freely but are still bound by strong attractive forces; incompressible and can be poured.

Gases (Kinetic Theory)

Particles have nearly overcome attractive forces and can move independently; can be compressed.

Energy

The capacity of an object to do work, measured in joules (J).

Kinetic Energy

Energy possessed by an object due to its movement. E_K = \frac{1}{2} mv^2

Potential Energy

Energy possessed by an object due to its position.

Temperature

Measure of the average kinetic energy of particles in an object.

Absolute Zero

Temperature at which all particles have no kinetic energy and have stopped moving (-273°C).

Internal Energy

The total energy possessed by all particles in a system (\Sigma Ekrandom + \Sigma Epposition).

Heat

Internal energy that is transferred from one object to another due to a temperature difference.

Kelvin, Centigrade (Celsius), and Fahrenheit

Scales used to measure temperature.

Kelvin Temperature Scale

Zero point based on the lowest possible temperature (absolute zero) and is directly proportional to the average KE of particles.

Conversion from Celsius to Kelvin

T (in K) = T (°C) + 273

Heat

The internal energy that is transferred from one object to another.

Heat Transfer

Heat transfer from the hotter system to the cooler system until an equilibrium temperature is reached.

Three Methods of Heat Transfer

Conduction, Convection, and Radiation

Heat Capacity

The quantity of heat (energy) required to raise its temperature by 1 oC (or 1 K).

Heat Capacity Formula

Qm/\Delta T

Specific Heat Capacity

The heat capacity per unit mass of a substance.- a material's resistance to temperature change quantifies how many joules of heat energy (J) are required to raise the temperature of 1 kilogram of a substance by 1°C (or 1 K). The higher the ‘c’, the smaller the change in temperature

Specific Heat Capacity Formula

Q=mcdeltaT. Temperature change is proportional to the amount of energy added to or removed from a substance

Power

The rate of energy transfer.

Power Formula

P = W/t = Q/t

Latent heat

the heat required to convert a solid into a liquid or vapour, or a liquid into a vapour, without change of temperature. is the energy added to or removed from a system to change the state of system. they change the spacing between particles (positional potential energy)

Latent Heat of Fusion

solid to liquid

Latent Heat of Evaporation

liquid to gas

Elastic Collisions

• Kinetic energy is conserved

• Momentum is conserved

• The objects bounce off each other.

• No energy is lost to sound, heat, or deformation

Inelastic Collisions

• Kinetic energy is NOT conserved
  (Some energy is lost as sound, heat, or deformation)

• Momentum is still conserved

• The objects may stick together after the collision.

Momentum

Momentum is the quantity of motion an object has and is defined as the product of its mass and velocity.

Momentum (p)=m×v\text{Momentum (}p\text{)} = m \times vrelates to Newton’s Third Law, as the equal and opposite forces during a collision cause equal and opposite changes in momentum, leading to the conservation of momentum in a closed system.

A change in momentum is impulse

Temperature

the measure of the average kinetic energy of the particles in a substance

Internal Energy

the total kinetic and potential energy of particles in a substance- determined by the average kinetic energy of particles (motion) can be determined by temperature, state, and the distance between the particles

Thermal equilibirium

When thermal energy transfer between systems stop.

Static Friction

a force that opposes the initiation of motion between two objects at rest in contact

Kinetic Friction

the force that opposes the motion of two surfaces that are sliding past each other.

Horizontal Components Slope Calculations

Used to calculate horizontal components of a forces

Impulsive Force

The force acting to change momentum

The relationship betwen Impulsive Force and Time

Inversely Proportional

Law of Conservation of Energy

Energy is not created or destroyed. Energy just transforms (changes form) and transfers (moves to other objects)

Law of Conservation of Momentum

The collective total momentum possesed by a set of objects before they collide and after they collide will be the same. But the individual momentums will usually change. Consider sign conventions

Tension

Tension is the force exerted by a string, rope, or cable when it is pulled. T=mg +ma. When there is a load- the tension is the load + individual mass. forces on the left + forces on the right=ma. Maybe use horizontal components. Heavier mass determines the acceleration.