UNIT 6 Flashcards
Energy (42 cards)
and SOOOOoooo
explain law of conservation of Energy
- energy can neither be created nor destroyed; it can only be transferred or transformed
- SOoooo the total amount of energy in an isolated system always remains constant
describe energy transfer
the movement of energy from one place to another
describe energy transformation
the changing of energy from one form to another
3
what is energy efficiency?
- rarely are machines able to convert all of one energy into another
- some energy is always lost to the surroundings
- our goal in creating machines is to make them as energy efficient as possible
whats the formula for energy efficiency?
energy efficiency= (quantity of usable energy / quantity of energy consumed ) x 100
what is the difference between heat and temperature
- temperature is the degree of hotness while heat is the quantity of hotness
what is temperature
the degree of agitation (the speed) of the particles of a substance
what is heat
total energy of all oving particles inside and object
+ something specific
what is specific heat capacity?
- the heat required to raise the temperature of 1 gram of a substance by 1°C
- each substance has its own specific heat value
how do you find the heat energy ? formula + symbols + units
Q = mcΔT
Heat energy: Q= joule (J)
Mass: m= grams (g)
specific heat capacity: c= J/g°c
change in temperature: ΔT= celcius (°C)
negative value indicates what?
that energy is being lost
how to find change in temperature (ΔT)
final temperature - initial temperature
1g of water = …
1ml of water
2
explain potential energy with the ball
- the ball is at the top of the hill
- gravity is pulling the ball down to the earth
why is potential energy considered to be an energy reserve
it must be transformed into another type of energy before it can apply a force
what is kinetic energy and aka the…
the energy an object possesses due to motion
- the energy of motion
2
explain kinetic energy using the ball
- the ball is rolling fown the hill
- the rolling ball can apply force on another object
when will the ball have the maximum kinetic energy?
at the bottom
what two factors affect kinetic energy
mass and velocity
what is the formula of kinetic energy + symbols +units
Ek= 1/2mv²
kinetic energy: KE or Ek = Joules (J)
Mass: m = kilograms (Kg)
velocity: v= (m/s)
how to find kilograms
divide by 1000
potential energy is the energy of …
POSITION
when will the ball have the least potential energy?
at the bottom
what two factors affect potential energy
mass and height
