AQA GCSE COMBINED SCIENCE TRILOGY
HIGHER TIER PHYSICS PAPER 1H
CERTIFICATION
GRADED A+
⩥ Energy is transferred. Answer: Mechanically (by a force doing work),
electrically (work done by moving charges), by heating or by radiation
(like light or sound)
⩥ When a system changes, energy is transferred. Answer: It can be
transferred into or away from the system, between objects in the system
or between different types of energy stores. Closed systems are where
neither matter nor energy can enter or leave. The net change in the total
energy of a closed system is always 0
⩥ kinetic energy. Answer: energy of motion - the greater an object's
mass and the faster it is going, the more energy there will be in its
kinetic energy store. Ek (j) = 1/2m(kg)v(m/s) squared
⩥ Raised objects store energy in gravitational potential energy stores.
Answer: lifting an object in a gravitational field requires work, causing
an energy transfer to the the GPE store of the object. Ep(j) =
m(kg)g(n/kg)h(m)
,⩥ Falling objects transfer energy. Answer: Falling objects transfer
energy from its GPE store to its kinetic energy store. When there's no air
resistance, energy lost from the GPE store = energy gained in the kinetic
energy store
⩥ Stretching transfers energy to elastic potential energy stores. Answer:
As long as the limit of proportionality has not been exceeded, Ee (j) =
1/2 k (N/m) e (m) squared
⩥ specific heat capacity. Answer: the energy required to raise the
temperature of one gram of a substance by one degree Celsius. E (j)
= m(kg) c(j/kgdegree) theta (degrees Celsius)
⩥ Conservation of energy principle. Answer: Energy can be transferred
but can never be created of destroyed
⩥ Dissipated energy. Answer: energy used up in a system, typically lost
due to work done by friction, 'wasted energy'
⩥ Phone energy. Answer: When you use the phone, energy is usefully
transferred from the chemical energy store of the battery in the phone,
but some of this energy is dissipated to thermal energy
,⩥ Closed system energy transfer. Answer: A cold spoon is dropped into
hot soup in an insulated flask, which is then sealed. Energy is transferred
from the thermal energy store of the soup to the useless thermal energy
of the spoon
⩥ Power. Answer: The rate at which work is done (watts). P(w) = E(j) /
t(s)
⩥ Powerful machine. Answer: One which transfers a lot of energy in a
short space of time
⩥ Conduction occurs mainly in solids. Answer: Conduction is the
process where vibrating particles transfer energy to neighbouring
particles.
⩥ Long definition of conduction. Answer: Energy transferred to an
object by heating is transferred to the thermal store, which is shared
across the kinetic store of the particles. The particles' collisions cause
energy to be transferred between particles kinetic energy stores.
⩥ thermal conductivity. Answer: the Mrs sure of the rate at which
thermal energy can travel through a material
⩥ Convection occurs only in liquids and gases. Answer: Convection is
where energetic particles move away from hotter to cooler regions
, ⩥ Convection longer definition. Answer: Unlike in solids, the particles
in liquids and gases are able to move. When you heat a region of a
gas/liquid, the particles move faster and the space between particles
increases. This causes the density of the region to decrease. Because
they can flow, the warmer and less dense region will rise above denser
cooler regions. If there is a constant heat source, a convection current
will be made
⩥ Radiators - convection currents. Answer: Energy is transferred from
the radiator to nearby air particles by conduction. The air by the radiator
becomes warmer and less dense. This warm air rises and is replaced by
cooler air. At the same time, the previously heated air transfers energy to
the surrounding and cools, becomes denser, and sinks. This cycle repeats
and causes a flow of air to circulate around the room
⩥ How to reduce unwanted energy transfers. Answer: Lubrication and
thermal insulation
⩥ Lubrication reduces frictional forces. Answer: When something
moves, there's at least one frictional force acting on it, causing some
energy to be dissipated. For objects that are rubbed together, lubricants
reduce the fiction between the object's surfaces when moved. Lubricants
tend to be liquids (like oil) to flow easily between objects and coat them
⩥ Insulation reduces the rate of energy transfer by heating. Answer:
Things to do to prevent energy loss through heating...
HIGHER TIER PHYSICS PAPER 1H
CERTIFICATION
GRADED A+
⩥ Energy is transferred. Answer: Mechanically (by a force doing work),
electrically (work done by moving charges), by heating or by radiation
(like light or sound)
⩥ When a system changes, energy is transferred. Answer: It can be
transferred into or away from the system, between objects in the system
or between different types of energy stores. Closed systems are where
neither matter nor energy can enter or leave. The net change in the total
energy of a closed system is always 0
⩥ kinetic energy. Answer: energy of motion - the greater an object's
mass and the faster it is going, the more energy there will be in its
kinetic energy store. Ek (j) = 1/2m(kg)v(m/s) squared
⩥ Raised objects store energy in gravitational potential energy stores.
Answer: lifting an object in a gravitational field requires work, causing
an energy transfer to the the GPE store of the object. Ep(j) =
m(kg)g(n/kg)h(m)
,⩥ Falling objects transfer energy. Answer: Falling objects transfer
energy from its GPE store to its kinetic energy store. When there's no air
resistance, energy lost from the GPE store = energy gained in the kinetic
energy store
⩥ Stretching transfers energy to elastic potential energy stores. Answer:
As long as the limit of proportionality has not been exceeded, Ee (j) =
1/2 k (N/m) e (m) squared
⩥ specific heat capacity. Answer: the energy required to raise the
temperature of one gram of a substance by one degree Celsius. E (j)
= m(kg) c(j/kgdegree) theta (degrees Celsius)
⩥ Conservation of energy principle. Answer: Energy can be transferred
but can never be created of destroyed
⩥ Dissipated energy. Answer: energy used up in a system, typically lost
due to work done by friction, 'wasted energy'
⩥ Phone energy. Answer: When you use the phone, energy is usefully
transferred from the chemical energy store of the battery in the phone,
but some of this energy is dissipated to thermal energy
,⩥ Closed system energy transfer. Answer: A cold spoon is dropped into
hot soup in an insulated flask, which is then sealed. Energy is transferred
from the thermal energy store of the soup to the useless thermal energy
of the spoon
⩥ Power. Answer: The rate at which work is done (watts). P(w) = E(j) /
t(s)
⩥ Powerful machine. Answer: One which transfers a lot of energy in a
short space of time
⩥ Conduction occurs mainly in solids. Answer: Conduction is the
process where vibrating particles transfer energy to neighbouring
particles.
⩥ Long definition of conduction. Answer: Energy transferred to an
object by heating is transferred to the thermal store, which is shared
across the kinetic store of the particles. The particles' collisions cause
energy to be transferred between particles kinetic energy stores.
⩥ thermal conductivity. Answer: the Mrs sure of the rate at which
thermal energy can travel through a material
⩥ Convection occurs only in liquids and gases. Answer: Convection is
where energetic particles move away from hotter to cooler regions
, ⩥ Convection longer definition. Answer: Unlike in solids, the particles
in liquids and gases are able to move. When you heat a region of a
gas/liquid, the particles move faster and the space between particles
increases. This causes the density of the region to decrease. Because
they can flow, the warmer and less dense region will rise above denser
cooler regions. If there is a constant heat source, a convection current
will be made
⩥ Radiators - convection currents. Answer: Energy is transferred from
the radiator to nearby air particles by conduction. The air by the radiator
becomes warmer and less dense. This warm air rises and is replaced by
cooler air. At the same time, the previously heated air transfers energy to
the surrounding and cools, becomes denser, and sinks. This cycle repeats
and causes a flow of air to circulate around the room
⩥ How to reduce unwanted energy transfers. Answer: Lubrication and
thermal insulation
⩥ Lubrication reduces frictional forces. Answer: When something
moves, there's at least one frictional force acting on it, causing some
energy to be dissipated. For objects that are rubbed together, lubricants
reduce the fiction between the object's surfaces when moved. Lubricants
tend to be liquids (like oil) to flow easily between objects and coat them
⩥ Insulation reduces the rate of energy transfer by heating. Answer:
Things to do to prevent energy loss through heating...
