Paper 1 AS electricity Flashcards
what is the relationship between length of wire and resistance
directly proportional, as length increases so does resistance
What is Newtons 3rd Law
for every force, there is an equal and opposite force
what is Newtons 2nd law
F=Ma
what is Newtons 1st law
law of inertia, an object at rest will stay at rest and an object in motion will stay in motion unless acted upon by an unbalanced force
what is the relationship between tension and angles
As the angle decreases, the tension increases. This is known as the cosine of the angle, as the angle decreases the cosine value increases resulting in higher tension.
what increases as the temperature of a metallic conductor increases
the amplitude of vibrations of the lattice ions
what happens in an inelastic collision
momentum is conserved but kinetic energy is not
why are safety features in cars related to momentum?
they increase the time taken for the momentum to change
what is a couple
equal and opposite coplanar forces
why shouldn’t lots of people stand on top of a bus?
the centre of mass will be higher and therefore a smaller tilt is required to move the buss’ centre of mass over the busses wheels
what is work done measured in
joules
what happens if force is perpendicular to the movement
no work is done
what is the area underneath a force - distance graph
work done
what is current
the rate of flow of charge
what is kirchoffs first law
the total current arriving at a junction is equal to the total current
what is the elementary charge
1.6 x 10^-19
why would it be dangerous to fire bullets upwards on the moon but not so much on earth
energy is conserved, it will be converted into GPE but back into KE at the same speed, there is no air resistance to convert into heat
explain the variation of resistance with potential difference for the filament bulb in terms of particle behaviour
as the voltage increases, the energy of electrons will also increase there will be a greater amount of collisions and therefore the temperature will increase. The amplitude of vibrations increase. Due to the increase of R the current does not increase in proportion
what are the units of a moment
Nm
do doors open easier when we push closer or further away
far away, the moment will be bigger
what is the centre of mass
a point through which an objects weight seems to act
what happens to an object if its centre of mass is outside its base
it will topple
when will an object fall off a surface
when its centre of mass is not above its surface
