parrot cards

Question 1

newtons first law

Answer 1

states that an object will remain at rest or move with a constant speed in a straight line unless acted upon by an unbalanced force

Question 2

the law of the conservation of linear momentum

Answer 2

states that the total momentum before a
collision/explosion is equal to the total momentum after the collision/explosion as long as no
external forces are acting.

Question 3

time dilation

Answer 3

is the increase in an observed time interval for an object moving relative to an observer compared to that measured when they are in the stationary frame of reference.

Question 4

length contraction

Answer 4

is the decrease in the observed length (in the direction of motion) of an object moving relative to an observer compared to that measured when they are in the stationary frame of reference

Question 5

standard model

Answer 5

12 fermions(matter particles):
6 quarks - up down , charm strange, top bottom
6 leptons - electron electron neutrino, muon muon neutrino , tau tau nuetrino

4 Gauge bosons
photon (electromagnetic force )
w boson(weak force)
z boson (weak force )
gluon(strong force )
possible graviton (gravity )

Question 6

potential difference

Answer 6

(voltage) is the number of joules of energy used to move one coulomb of charge between two points

Question 7

constructive inference

Answer 7

when two coherent waves meet in phase they combine to produce a maximum

Question 8

desructive interference

Answer 8

when two coherent waves meet exactly out of phase they cancel out to produce a minimum

Question 9

absalute refractive index

Answer 9

of a medium is ther ratio of the speed of light in a vacuum to the speed of light in the medium

Question 10

the critical angle

Answer 10

of a medium is the angle of incedence inside the medium which resukty in a refracted angle of 90 degrees in a vacuum

Question 11

an alternating current

Answer 11

is one which changes direction and instantaneous value with time ie the charges are continually changing direction

Question 12

the e.m.f

Answer 12

is the number of joules of energy given to every coulomb of charge as it passes through the power supply/battery. a battery of 12 volts would have 12 J emf

Question 13

an LED (LIGHT EMITTING DIODE)

Answer 13

is a forward biased p-n junction. electons cross from the conduction band of the n -type to th conduction band of the p type where they release energy as a photon of light as they fall into the valence band of the p type