Efficiency
What is the formula to find efficiency?
Efficiency % = Useful energy/ Total energy * 100
What is the formula used to find energy added when heating a substance.
Q = M C deltaT
Look at the graph. Identify the values for y and x.
y = Energy added
x = Temperature
Which type of nuclear decay has the highest penetration ability.
Gama
What temperature is Absolute Zero?
-273.something something Celsius, or 0K
Look at the graph, Identify the Current that produced the highest efficiency.
8Amp
Explain why the temperature of a substance doesn't change during the evaporation stage.
Energy is going into breaking bonds rather than increasing the temperature of the substance.
Look at the graph, what would the gradient be = to?
g = m*c
What problem will cause a nucleus to undergo Beta Decay?
Imbalance in proton to neutron ratio
What is Mr Smiths Favourite Element?
Thorium
Look at the graph, what current produced an efficiency of 90%.
2.8-2.9 Amps
Explain why metal feels cooler to the touch than wood when at room temperature.
Metal has a lower specific heat capacity meaning that it is much more conductive of the heat. The cool feeling you experience is energy flowing from your hand into the metal and not into the wood.
Find the absolute uncertainty of the gradient.
+ or - 19.72
What sort of decay will large nuclei undergo?
Alpha decay.
What does AC DC stand for?
Alternating Current
Direct Current
If a light bulb is supplied with 240J of energy and creates 180J of light energy. What is the efficiency of the light bulb.
75%
A student decides to determine the latent heat of fusion of water by performing an experiment where she measured the heat required to melt 0.5kg of ice at 0C. She found that her 1000 W heater had to run for 120 seconds to completely melt the ice to water at 0C.
Calculate the Value for the latent Heat of fusion of the water from the experiment.
80000J/kg or 8*10^4J/kg
If the Mass is = 2kg calculate the value of the specific heat capacity.
130
What is the daughter nucleus when caesium 137 undergoes beta negative decay?
Barium 137
What is a boson?
A force mediating particle.... or is it a wave....
Look at the graph, If 500J of energy is supplied at 2Amps, how much energy is wasted?
60J
The ideal temperature for hot drinks is 75C. What volume of milk at 5C should be added to bring 220mL of water at 90C down to 75C? Assume milk has the same specific heat capacity as water and that 1mL of milk/water weighs 1g.
47ml
If the substance being heated has a mass of 2.5kg calculate the specific heat capacity when it is a liquid.
20 J/Kg/K
Plutonium 242 undergoes three successive alpha decays followed by a beta negative decay, what nucleus is formed at the end of this decay sequence?
Actinium 230
What did Albert Einstein win his Nobel prize for?
The photoelectric effect