At what position on earth is escape velocity lowest? - correct answerlargest initial speed/ke from earth's
rotation
Boyle's law - correct answerfor a fixed mass of ideal gas at a constant temperature, the pressure is
inversely proportional to the volume, V = k/P
Charles' Law - correct answerfor a fixed amount of ideal gas at a constant pressure, the volume is
directly proportional to the absolute temperature V = kT
common silly mistakes to avoid - correct answer- diameter is not radius and radius is not diameter
Coulomb's Law - correct answerthe force acting between two charges is:
- directly proportional to the product of the charges
- inversely proprtional to the square of their separation
faraday's law - correct answerThe magnitude of the induced emf is directly proportional to the rate of
change in magnetic flux linkage
first law of thermodynamics - correct answerThe internal energy of a system is increased when energy is
transferred to it by heating or when work is done on it
gravitational potential at a point: - correct answerenergy required to move a point mass of 1kg to a
point in the field from infinity
how do you know what happens to energy stores of a substance when it changes state? - correct
answer- if temperature is constant, so is KE, while PE changes (increasing for melting and vaporisation)
- if temperature isn't constant, KE is changing (increases if temperature increases, decreases if
temperature decreases), while PE remains the same
, How does dielectric cause change in capacitance - correct answer- polar molecules align with their
positive side facing the -ve plate
- producing a counter electric field
- the pd reduces between capacitor plates but charge remains the same so capacitance increases since C
= Q/V
how does energy transferred change the sample arrangement of its atoms when the sample has
constant temperature and is changing state - correct answerif melting or vaporising, energy is
transferred to the sample('s PE store) reducing the number of nearest atomic neighbours.
if condensing or freezing, energy is lost from the sample to the surroundings, increasing the number of
nearest atomic neigbours
how is nuclear waste dealt with? - correct answer- cooling ponds
- vitrified (made solid into glass)
- placed in lead containers to be stored DEEP underground in a geologically stable region
(handled with robots)
How to avoid silly mistakes: - correct answer- Only use variables in calculations and sub everything in at
the end with plenty of space.
- If struggling with a question, look back at what you did before
- attempt to see if your answer makes sense in the context of the question
- don't sub in only part of the equation, ensure you leave subbing in to the end
how to make a transformer close to 100% efficiency? - correct answerlaminate the core to reduce eddy
currents
if you know the mass of a gas what is
molar mass of that gas = - correct answermass * N_a / number of atoms
if you know the mass of a gas what is