Past Paper Flashcards
On a graph showing count rate and time for the decay of a sample, why should you not expect the points to lie exactly on the lines of best fit?
Decay is random
How should you get from kg to newtons?
Times by 10 (correct is 9.81)
The load has a mass of 400g and gains 3.2 joules in its gravitational store when lifted. What amount of useful work done does the motor do?
3.2j
How should you allow for background radiation when doing an experiment?
Use a GM tube
Remove source from the experiment
Record the count rate
What is the definition of specific heat capacity?
Energy required per gram of mass to change per unit temperature
How does a main sequence star evolve into a supernova?
Hydrogen fusion stops
So the core collapses
Which restarts fusion
It will then form into a red supergiant
Fusion of the heavier elements stops
This will then explode
what are examples of ionising radiation?
x-rays
gamma rays
Ultraviolet
are charge and powers scalars or vectors?
scalars
what fuel is used in a nuclear power station?
uranium
platonium
how is a main sequence star formed from a nebula?
nebula is cold
gravity causes it to collapse
temperature increases
creating a protostar
it is created when fusion begins
how does a main sequence star become a white dwarf?
hydrogen fusion stops
core colapses
core temp increases
star expands to become a red(super)giant
surface temp decreases
helium fusion begins
white dwarf is formed when helium fusion stops
the rest of the star is released
give two uses of total internal reflection
optical fibres
binoculars
how does voltage compare when in parallel?
it is the same
what happens to current in a parallel circuit?
splits
what is voltage?
the force that makes electrons flow
what is current?
the rate the electrons flow
how does a cardboard box with layers prevent energy transfer by conduction?
it is a poor conductor
air is a gas which is a poor conductor
particles in air are far apart
thicker objects conduct slower
