physics paper 1 Flashcards
(36 cards)
parallel circuits
voltage same
current shared
resistance is less than the lowest resistance
series circuits
voltage shared
current same
resistance shared
a fluid Is compressed by pushing the plunger into the body of a sealed syringe
what’s happening
theres a force at 90 to all points on the surface of the fluid
why is a variable resistor needed
to control the current in the circuit
describe how you use this experiment and a compass to investigate the magnetic field produced by the wire
place the compass on the card
plot the direction of the needle
now put the tail of the compass at the tip of the arrow drawn
keep going until you’ve reached the other end
repeat at different distances from the centre
how does a magnetic compass show that the Earth’s core is magnetic
the compass ALWAYS points north no matter where you are
explain how the charged rod affects the stream of water
rod attracts water
opposite charges attract
the water has both + and - charges
conditions needed for charge to flow
potential difference
closed circuit
explain how students can determine an accurate value for the specific latent heat of water
measure the initial mass of a beaker
turn on the heater and start timing
use the voltmeter, ammeter and stop clock to calculate the energy supplied through the heater (E=VIt)
turn off the heater and stop timing
use a balance to measure the mass of the beaker and melted ice
subtract the original mass of the beaker to find the mass of the melted ice
calculate the specific latent heat by dividing energy by mass
make sure the heater is always covered with ice
insulate the funnel to reduce heat loss from the funnel
repeat the experiment to minimize random errors
what is conserved in an elastic collision vs inelastic collision
elastic:
momentum
kinetic energy
inelastic:
momentum
why is the mass of water the same as the mass of melted ice
there’s a conservation of mass because there’s a conservation of the number of particles
figure out the specific heat capacity of water
put water in a beaker
measure the initial temperature
turn on the heater for a set amount of time
measure the voltage and current to calculate the energy
measure the end temperature
calculate the temperature change
explain, using ideas about particles, how temp affects gas pressure
As temp increases,
gas particles have more kinetic energy
they move around more so
they collide more frequently with the walls
creating a bigger force
which means greater pressure
why is a plastic ruler not normally charged and why it becomes charged when a student rubs it with a cloth
the ruler has an equal number of protons and electrons so their charges cancel out
however when rubbed with a cloth, electrons are transferred to the cloth and the charges are no longer equal
why does the resistance increase when the current increases
more current means, ions vibrate more
more vibrating means more collisions
more collisions make it harder for electrons to pass through
which increases temp, which increases resistance
explain why a boat of concrete floats but a lump of concrete sinks
boat has a bigger upthrust compared to the lump
and that upthrust is equal to the weight of the boat
the weight of water is displaced by the boat is equal to the weight of the boat
overall density of the boat includes the air
and the overall density of the boat is less than the density of the water
why is the mass of the trolley lower than found in the experiment
not all energy is transferred to the trolley
it assumes all force on the trolley is equal to the weight added on the string
there’s friction on the pulley
the mass of the string/card is ignored
the card on the trolley isn’t measurely properly
the card didn’t pass through the light gates vertically
fleming’s left hand rule
thumb - force
first finger - field
second finger - current
solenoid
a coil of wire carrying an electric current, creating a magnetic field
increase number of turns
increase current
use a soft iron core
inertia
a measure of how difficult it is to change the velocity of an object
why is the actual energy needed to turn water to steam more than calculated in an experiment
some of energy is used to heat the container
heat is lost to the environment
Simple model of earth’s atmosphere
Uniform density
Single layer of gas 700km
Thickness of atmosphere is small compared to the diameter of Earth
Variable resistor
Box with the arrow going thru
Thermistor
Box with the hockey stick
