Definitions WJEC As Physics Flashcards
Principle of moments
For equilibrium- Total Clockwise moments = Total Anti-Clockwise moments
center of gravity
The gravitational center of a body where the entire mass can be considered to act.
Newton’s 1st law
Every object will remain in uniform rest or uniform motion unless acted upon by another force.
Newton’s 2nd law
Force is equal to Mass * Acceleration AKA F = MA
Newton’s 3rd law
Every interaction has an equal and opposite one.
Momentum
Momentum = Mass * Velocity AKA P=MV
Elastic/Inelastic collision(s)
Elastic - no change in total kinetic energy before and after collision.
Inelastic - loss in total kinetic energy before and after collision.
Work done
The work done is equal to the force exerted times by the distance. W = FD
Conservation of energy
Energy cannot be created or destroyed only transferd.
Potential energy from gravity
The amount of stored or potential energy that an object has due to gravity. Ep = MGH
Kinetic energy
The energy possessed during motion by an object. 1/2(M(V)^2)
Elastic potential energy
1/2FX or 1/2((K^2)X)
Hooke’s law
The tension in a spring or wire is proportional to the extension.
Spring constant
Force per unit extension.
Stress in a wire or spring
Force per unit area
Strain in a wire or spring
Force per unit length
Young Modulus
Stress / Strain
Black body
A body that absorbs all waves of light on the
Wien’s displacement law
Wavelength is inversely proportionally to the temperature
lamda max = W/T
W = 2.9 * 10^-3
Stefan’s law
Power = Area * Sigma * Temperature^4 = Luminosity
Intensity
I = P / 4Pir^2
Lepton
electron + electron neutrino
Hadron
particles of quarks and anti-quarks
Baryon
3 quarks or anti-quarks, protons and neutrons
