2019 Paper 2 (10/02/2025) Flashcards
Total Energy to change state equation?
E total = E temperature + E state
E total = mcΔt + ml
Work done equation in thermal?
W = p ΔV otherwise W = p (V1 - V2)
Internal Energy?
Sum otherwise total of kinetic and potential energies of molecules otherwise atoms or particles that move randomly in the gas
Absolute zero temperature with ideal gas laws and kinetic energy?
Absolute Zero temperature is when the temperature is 0k. The equation for ideal gas is: PV = NRT which means when T=0 the pressure and volume also equal 0. The equation for kinetic energy is: Ek = 3/2kT which means when T=0 the kinetic energy also equals 0
Mean kinetic energy and same temperature significance?
At the same temperature otherwise equilibrium, both gases have the same average kinetic energy
Pressure exerted by gas?
Particles otherwise atoms collide with the walls resulting in a change of momentum. The walls provide a force equal to the change in momentum. The particles give a force on the walls resulting in a pressure being created since pressure is the force per unit area
If gas stays the same how can pressure be reduced?
Volume could be increased. This increases the time between collisions which causes less frequent collisions with walls which reduces the rate of change of momentum. The temperature could be reduced. This reduces the momentum change at the wall and increases the time between collisions otherwise reduces frequency of collisions which reduces rate of change of momentum
Gravitational Potential at a point?
Work done otherwise energy required in bringing a unit mass otherwise 1 kg from infinity to a point
How to use equipotential lines to work out mass?
Use the Gravitational potential energy and distance from the centre of any line and put into equation V = GM/r re-arranged to M = Vr / G where V is the gravitational potential energy and r is the distance from centre.
Forces on charged spheres in equilibrium?
Tension going up into string holding sphere. Weight vertically down underneath the centre of the sphere. Electrostatic force on furthest part of sphere and outwards in direction perpendicular to weight
Issues measuring the distance between charged spheres?
Difficult of measuring distance between curved objects. Separation distances could be affected by measuring through accidentally moving or touching altering reading. Instruments between spheres could change permittivity
R^2 of two charged spheres in equilibrium?
It the distance between both centres of the spheres
Flux Linkage and EMF graphs?
The magnetic flux linkage graph against time will follow the same trajectory as the emf against time graph but will be 90 degrees out of phase behind the EMF against time curve
KE of neutrons reduced in thermal nuclear reactor?
To increase the chance of fission when a neutron collides with a fissile material
Collisions dependant on nucleon number of moderator?
Collisions are elastic as nucleons collide with nuclei and are ejected off and transfer some momentum. If a neutron collides with a neutron the first neutron stops and the other carries on which shows all energy is transferred. But, if it’s larger the less energy that is transferred and the more it will be ejected back with its initial speed. This means for atoms which are larger and have more nucleons need more collisions as each collision transfers less KE
Converting “U” to “MeV”?
Multiply the value of “U” by 931.5
Benefits of Nuclear Power?
Less pollution created means cleaner air as less carbon dioxide is produced with no fossil fuels being burned. Small amounts of fuel consumed to get the same amount of energy. Nuclear power can be produced constantly and some nuclear power stations can adjust their output quickly. Medical isotopes can also be produced.
Planet rotates so quickly that material at its equator only just remain on surface?
This means all other material on the planet become satellites
Levitating plates meaning?
Levitating plates means there’s a force pulling up and a force pulling down and this is mg=EQ which is the magnetic force being equal to weight
Field Lines show?
Field lines show direction of force on a positive charge
Aluminium sheet making count rate become background count?
Alpha and beta as if it were gamma it would pass through and this result wouldn’t happen
Current induced when magnet falls through conducting ring?
A current can only be induced if the conducting ring is a complete loop
“X” direction and “Y” direction on oscilloscope trace?
The x-direction is the time base setting and the time base is the value of each square in the x-direction. The y-direction is the Y-Voltage gain and each square in the y-direction is equal to the magnitude of the Y-Voltage gain
Effect of control rods?
When lowered the absorb fission neutrons and lowers their total but has no effect on their average kinetic energy
