Physics Paper 1 Flashcards
What are some scalar ?
• temperature, speed, distance, mass, time, energy, work done, power
What are some vectors ?
• force, velocity, displacement, weight, acceleration, momentum
Equation to fine acceleration
• acceleration= v - u / t
Equation linking acceleration & distance
V2 - U2 = 2 x a x x
Equation to calculate weight
• weight = mass x gravitational field strength
What are the 8 energy stores ?
• kinetic energy, GPE, thermal, EPE, electrostatic, magnetic, nuclear, chemical
What are the 4 ways energy can be transferred ?
• mechanical-> forces
• electrically-> electric current flows
• heating-> thermal energy flows
• radiation-> waves
What are the methods to reduce unwanted energy transfers ?
• lubrication, cavity wall insulation, double glazing, thicker loft insulation, carpet & underfloor insulation, draught excluders, fitted curtains, shiny foil
What happens when atoms absorb electromagnetic radiation ?
• electrons jump to higher orbits-> they become excited-> they go back to lower orbits it as they lose energy-> release glowing light
What are the properties of alpha particles ?
• 2 protons, 2 neutrons
• low penetration
• highly ionising
What are properties of beta particles ?
• beta minus-> fast moving electrons-> charge -1
• beta plus-> fast moving positrons-> charge +1
• moderate penetration
• moderate ionising
What are the properties of gamma rays ?
• short wavelength
• no mass no charge
• most penetrating
• low ionising
What is radioactive contamination?
• when a object gets radioactive source in it or on it
What is radioactive irradiation ?
• object exposed to radiation from external source
What are transverse waves ?
• vibrations perpendicular to direction of wave travel
• light & electromagnetic waves
What are longitudinal waves ?
• vibrations parallel to direction of wave travel
• sound waves
What happens when waves pass from one medium to another (refraction) ?
• wave will refract at boundary & change direction to bend towards normal
• speed decreases
• wavelength decreases
• energy of wave is constant
• light bends closer to normal
What are electromagnetic waves ?
• transfer energy from source to observer
• transverse waves
• all travel at same speed in a vacuum
What is the order of increasing frequency & increasing wavelength ?
• radio-> micro-> infrared-> visible-> ultraviolet-> xray-> gamma
• opposite for increasing wavelength
What are the relationships of the waves ?
• as wavelength decreases-> frequency increases
• as frequency increases-> energy of wave increases
What are the dangers of the electromagnetic waves ?
• micro-> internal heating of body cells
• infra red-> skin burns
• UV-> damage to surface cells & eyes, leading to cancer
• xray/ gamma-> mutations, damage to cells
What are the uses of electromagnetic waves ?
• radio-> communications
• micro-> cooking
• infrared-> thermal imaging
• visible-> photography
• UV-> security marking
• Xray-> airport scanners
• gamma-> sterilising food
