Physics Grade 11 Flashcards
What is kinetic energy?
Energy an object has because of its motion
What is thermal energy?
energy contained within a system that is responsible for its temperature.
What is specific heat capacity?
the thermal energy required to raise the temperature of 1kg of a substance by 1℃ or by 1K.
What is specific latent heat?
he amount of energy required to change the state of 1 kilogram (kg) of a material without changing its temperature
What is thermal equilibrium?
the situation when there is no net exchange of thermal energy between components of a system. i.e. the components have the same temperature and thus the average kinetic energy of the particles is the same
What is Heat?
energy in the process of being transferred from one place to another due to the temperature difference.
What is temperature?
a measure of the average kinetic energy of the particles that make up a substance.
What is internal energy
the total microscopic kinetic energy, and microscopic potential energy of the particles in a system. It does not include macroscopic energy.
what is the concept of proportionality
Energy put into different substances does not result in the same temperature rises
why does temperature in a system remain the same during a change of state?
The addition of thermal energy does not go into changing the kinetic energy of the particles but into changing the potential energy
what is specific latent heat of vaporization
The amount of thermal energy required to change 1kg of a liquid at its boiling point into a vapor.
What is the zeroth law of thermodynamics
If two bodies are in thermal equilibrium with a third body, they are in thermal equilibrium with each other’.
what is the first law of thermodynamics, Work done on the system?
The increase in the internal energy of a system is equal to the amount of heat added to the system, plus the amount of work done on the system.
What is the first law of thermodynamics, work done by the system?
The increase in the internal energy of a system is equal to the amount of heat added to the system, minus the amount of work done by the system.
What is the first law of thermodynamics?
The internal energy of a system has to be equal to the work that is being done on the system, plus or minus the heat that flows in or out of the system and any other work that is done on the system.”
what is thermal efficiency?
Thermal efficiency is the ratio of useful work out of a machine or in a process, total energy expended or heat taken in
Why do protons repel each other
opposite charges attract and the same charges repel
what is the strong nuclear force
holds protons and neutrons together in the nucleus.
explain natural radioactive decay
outside the island of stability, the nucleus undergoes natural radioactive decay and breaks apart because of the instability caused by the competing electrostatic force and the strong nuclear force.
what is alpha radiation
a stream of particles each consisting of two protons and two neutrons emitted from the nucleus of some radionuclides.
what is alpha decay
Alpha decay occurs when there are too many protons and neutrons (i.e. too much mass).
beta negative decay
when there is a surplus of neutrons for how many protons there are
Beta positive decay
Beta positive decay occurs when there are too many protons in the nucleus for the number of neutrons.
gamma decay
a release of energy that originates from within the nucleus.
what is a nuclear decay series
A decay series refers to a sequence of nuclides formed by successive radioactive decays until a stable decay product (the last nuclide in the series) is formed.
What is a half life
the time for half the radioactive nuclei in any sample to undergo radioactive decay; or,
The amount of time taken for the number of nuclei present in a sample at a given time to exactly halve.
What is artificial transmutation
an induced nuclear reaction by means of bombardment with a projectile of fundamental particles
nuclear fission
An artificial nuclear reaction in which a large unstable nucleus splits, forming two (or more) smaller, more stable nuclei and releases energy and neutrons.
Nuclear fusion
Nuclear fusion is the process by which two light atomic nuclei combine to form a single heavier one while releasing massive amounts of energy.
mass defect
Mass defect is defined as the difference between the mass of the atom and the sum of the masses of its component protons, neutrons and electrons
conservation of charge
The net amount of charge produced in any transfer process is zero the net amount of charge lost by one object is gained by the other.
Electrical potential difference
Potential difference (p.d.; ∆V) is the difference in electric potentials between two points in an electric field.
Electric current
the rate of motion of electric charge carriers from one part of a conductor to another.
Electrical resistance
a measure of its opposition to the flow of electric current.
Ohms law
Electric current is proportional to voltage and inversely proportional to resistance.
scalar
quantities containing only magnitude
vector
quantities containing magnitude and direction
Displacement
it is the object’s overall change in position.
velocity
the rate at which an object changes its position
Acceleration
rate of change of an object’s velocity with respect to time
Newtons first law
an object maintains its state of rest or constant velocity motion unless it is acted on by an external unbalanced force.
Newtons 2nd law
the acceleration of an object is in the direction of the net external force acting on it and proportional to the size of the force and inversely proportional to the mass
Newtons 3rd Law
for every action there is an equal and opposite reaction’, but this implies that the reaction follows the action.
Momentum
Momentum is the quantity of motion of a moving body
Impulse
the effect of force acting over time to change the momentum of an object.
law of conservation of momentum
For two objects colliding in an isolated system, the total momentum before and after the collision is equal
elastic collisions
A collision where kinetic energy and momentum are conserved
inelastic collisions
A collision where momentum is conserved but kinetic energy is not.
kinetic energy
Energy due to the motion of an object, including the motion of particles in a substance
gravitational potential energy
Energy stored in an object due to its position relative to another object to which it is attracted by the force of gravity
mechanical waves
Waves that require an elastic medium (e.g. air or water; not in a vacuum) for the transfer of energy.
Reflection
Reflection is the process where incident waves at a boundary change direction returning into the same medium.
Superposition
When two or more waves overlap in space, the resultant wave is the algebraic sum of the individual waves
Standing wave
those with stationary vibration patterns formed due to the superposition of waves with particular frequencies.
Refraction
The process when incident waves at a boundary change direction and speed when passing into another medium.
Diffraction
The process by which waves either bend behind a barrier or the wavefront is broken up into many small sources.
Resonance
Resonance occurs when a vibrating object or external force causes another system to oscillate with greater energy at a particular frequency.
Natural frequency
The frequency at which an object tends to vibrate with when hit, struck, plucked, strummed or somehow disturbed is known as the natural frequency of the object.
Intensity
the average rate of flow of energy per unit area’.
snells law
When light travels from one medium to another, the ratio of the sine of the angle of incidence to the sine of the angle of refraction is equal to the refractive index (n).
