Law of conservation of energy Flashcards
The sum of the kinetic and potential energy of the particles that make up an object
Thermal energy
transfer of energy by electromagnetic waves
Radiation
Transfer of thermal energy by collisions between the particles that make up matter
Conduction
Transfer of thermal energy in a fluid by the movement of warmer and cooler fluid from one place to another
Convection
stove
thermal energy
toaster
Thermal energy
Ironing clothes
Conduction
Ice melting,
Conduction
Iron
Thermal energy
hot air balloons,
Convection
x-rays,
Radiation
Computer CPUs
Conduction
Car Engine Cooling,
Conduction
remote controls.
Radiation
Fireplace
Thermal energy
metal spoon
Conduction
ultraviolet light,
Radiation
Lighting a Match
conduction
Hot Coffee in a Mug.
conduction
Wi-f- signals, remote controls, MRI scans
Radiation
cooking on a gas stove
Conduction
Boiling water,
Convection
radio waves,
Radiation
Sea and ocean currents,
Convection
cooking in ovens,
Convection
Hair dryers,
Convection
Microwave
Thermal energy
greenhouse effect
Convection
sunlight
Radiation
microwave ovens,
Radiation
MRI scans
Radiation
First Law of Thermodynamics states that if the mechanical
energy of a system is ___,
the increase in thermal energy of
that system equals the ___
1.constant,
2.sum of
the thermal energy transfers into
that system and the work done
on that system.
Second Law of Thermodynamics states that energy ___. Systems always
move to more stable ___
1.spontaneously
spreads from regions of higher
concentration to regions of lower
concentration.
stable states, or
states with uniform energy
distribution.
Example of 1st law
Increase temperature of your
hands by warming them near a fire and by
rubbing them together
2nd law example
Heat from radiator transfers to
cat but not the reverse
The faster particles move,____
the higher the thermal
energy and the warmer an object becomes.
Greenhouses use s____ to____. Heat
enters the greenhouse through its covering of ___ and starts to warm the ___.
The warmed air near the soil begins to ____ and is
immediately replaced with _____. This cycle raises the temperature
inside the greenhouse more rapidly than the air outside,
creating a sheltered, warmer microclimate
1.solar radiation to trap heat
2. covering of glass or
plastic
3.soil and plants inside
4.rise
5.cooler surrounding air that
starts to heat up
A vacuum is an extremely ____. a vacuum between the two outer walls of a thermos bottle ___. It limits or
reduces the transfer of energy between
the bottle’s contents and its surroundings.
This keeps the temperature of the
contents of the thermos at its original
temperature.
1.Good insulator
2.minimizes the transfer of thermal energy from conduction and convection.
If a piece of paper is placed between two colliding spheres as shown below, holes will
be burned in the paper where the steel spheres meet. Describe all the
transformations of energy between the two steel spheres and the paper.
1.After the spheres collide, the
particles of matter in the spheres
begin to vibrate faster which
increases the thermal energy of
the particles.
2. The force of the colliding spheres
causes the thermal energy of the
paper to increase, which burns the
hole in the paper
Identify and give an example of 3 ways electrical energy is
converted to other types of energy such as mechanical,
light, thermal, or sound energy
Identify and give an example of 3 ways electrical energy is
converted to other types of energy such as mechanical,
light, thermal, or sound energy
Mechanical
1.Can opener
2.Mixer
3.Drill
Light
1.flashlight
2.lamp
3.car headlight
thermal
1.toaster
2.oven
3.hair dryer
Sound
1.radio
2.cell phone
3.alarm clock
Potential Energy-
stored energy
formula
PE = mgh
m
mass in kilograms
g
acceleration due to gravity (9.8 m/s2)
h
height in meters
Units
(kgm/s2)m = newton*meter = Joules
Calculate the boulder’s
gravitational
potential energy at its
highest point.
Boulder’s mass is 8 kg.
Distance A is 20 m.
Distance B is 10 m
Calculate the boulder’s
gravitational
potential energy at its
highest point.
Boulder’s mass is 8 kg.
Distance A is 20 m.
Distance B is 10 m
Kinetic energy
energy of motion
formula
~KE = ½ mv2
m
mass in kilograms
v
velocity in meters/sec
Units
(kgm/s2)m = newton*meter = Joules
Example:
The bird has a mass of 2 kg. It is flying at a
velocity of 5 m/s East. Find its kinetic
energy.
KE = ½ mv2
Example:
The bird has a mass of 2 kg. It is flying at a
velocity of 5 m/s East. Find its kinetic
energy.
KE = ½ mv2
Kinetic & potential energy convert
to one
another = energy not lost or gained.. Just
transferred
Types of Potential Energy:
Elastic, Chemical and Gravitational
Energy Transformations in Roller Coasters
Energy Transformations in Roller Coasters
Transformation #1
mechanical energy used to move the roller coaster cars to the top of
the first hill so mechanical energy to kinetic energy
Transformation #3
mechanical energy is once again used to bring the roller coaster cars to
a stop at the end of the ride. Friction of metal brakes may produce
thermal energy.
Transformation #2
at the top of the hill the roller coaster car has a great amount of
gravitational potential energy that is transformed into kinetic energy as
the roller coaster cars go down the hill
- Three ways that wind turbines
transform energy.
Kinetic Energy to Mechanical Energy:
wind flows past the turbine blades causing
them to rotate
Mechanical Energy to Electrical Energy:
electrical energy
Rotating blades then turns a generator to produce
3) Power conversion and distribution:
electricity generated is converted to alternating current (AC) and
transmitted through power lines to homes and businesses
Elastic Potential Energy
Energy stored in objects that can be stretched or compressed, like springs or rubber bands.
Chemical Potential Energy
Energy stored in the bonds between atoms and molecules, released during chemical reactions.
Gravitational Potential Energy
Energy an object has due to its height above the ground, depending on its mass and height.
