Energy and Forces I Flashcards
units for energy
- Joules
- Kilo Joules
abbreviations for energy units
- J
- KJ
how many J in a KJ
1000
how many KJ in a J
0.001
thermal energy store (2)
- energy store for how hot/ cold an object is
- some energy always there because it is physically impossible for an object to be less than -273 degrees Celsius
what is the lowest possible temperature on earth
-273 degrees Celsius
kinetic energy store
there will be energy in an object’s kinetic energy store if the object is moving
chemical energy store
high in fuels, food and muscle tissue
gravitational potential energy store
the higher an object is from the ground, the higher the gravitational potential
how much gravitational potential energy is in an object that is on the ground
0
how much kinetic energy is in a stationary object
0
Law of conservation of energy
energy cannot be created or destroyed
energy can be stored or transferred
if someone eats food and then runs where does the energy initially come from
chemical energy of the food
if someone eats food and then runs where does the energy get transferred to next
chemical energy store of muscles
if someone eats food and then runs where does the energy end up last
kinetic energy store of muscles AND thermal energy store of surroundings
if someone burns wood where does the energy initially come from
chemical energy store of the wood
if someone burns wood where does the energy get transferred to
kinetic and thermal energy store of the fire
if someone burns wood where does the energy end up last
thermal energy store of surroundings
what are 2 energy transfer mechanisms
weight/ gravity and waves
what is gravity
the force that brings all objects with mass closer together
what is the gravitational field strength on earth
9.8 N/kg
weight
a force measured in Newtons that is affected by the mass and location of an object
mass
measured in grams or kg and does not change, whatever the gravitational field strength might be
formula for weight
weight (Newtons) = mass (kg) x gravitational field (N/kg)
