energy Flashcards
What’s kinetic energy
kinetic energy is energy stroed in moving objects
What’s gravitational potential energy?
Enrgy stored in objects due to its gravity
What’s thermal energy
energy stored in hot objects
What’s elastic potential energy?
Energy stored in objects squahy and stretchy objetcs
equation for kinetic energy
K.E. = 0.5m v2
equation for gravitational potential energy
U=m g h gravity is 9.8
how much is gravity
9.8
What’s the conservation of energy?
Energy cant be created or destroyed, it can only be transformed or transferred
equation for thermal energy
Change in thermal energy = mass x specific heat capacity x change in temperature.
what’s the equation for elastic potential energy?
U = 0.5kΔx
what does kΔx stand for
is the spring constant, and x is the displacement of the object from its rest position.
What’s chemical energy
Energy stored in chemical bonds.
What’s nuclear energy
: Energy stored in the nucleus of an atom.
what’s Electrostatic Energy
Energy due to the interaction of charged particles.
What’s Magnetic Energy
Energy due to magnetic fields.
How can energy be transferred?
Energy can be transferred mechanically (force doing work)
electrically (charge doing work)
Heating
Radiation (light, sound).
Equation for work done
W=F×d (force × distance
When is work done?
Work is done when a force moves an object.
what’s work measured in?
joules (J).
What’s power?
Rate of energy transfer or work done.
equation of power
P=E/t or P= W/t
What’s a closed system
A closed system is something where no matter (like gas or liquid) can go in or out, but energy can still move in or out.
E.g of a closed system
A sealed bottle is a closed system: no water can escape, but heat can enter or leave
What are Fossil Fuels?
Coal, oil and gas.
What’s renewable energy?
Energy that can be used again and cant run out
e.g o renewable energy
sunlight water wind
what’s non renewable energy?
energy that cant be used again and they run out
e.g of non renawable energy
coal oil natural gas nuclear fuels
What’s a system
a single or group of objects
What’s Watt
unit of power
Equation for effiency
Efficiency = useful power out ÷ total power in.
Specific Heat Capacity equation
energy = mass × specific heat capacity × temperature change
equation for power
Power = energy tranferred÷time
or
work done÷time
energy transfer
Energy can be transferred usefully, stored or dissipated but cannot be created or destroyed
equation for energy
power × time
what are the 2 types of work done
electrical and mechanical
What’s chemical work done?
chemical work done is using force to move an object.
E.G Kiking a ball- chemical energy store from leg is being transferred to the ekinetic energy to the ball
What’ electrical work done?
When a current flow.
energy requires too overcome the resistance in the wires of the circuit.
e.g- in order a train to stop, it applies breaks, which creates friction between brakes and wheels. then it transfers heat to the surrounding.
equation for power in terms of energy transfer
P=E÷t
p- power
E-energy
t-time
equation for power in terms of work done
P=W÷t
p-power
W-work done
t- time
what’s power measure in
Watts
What’s work done measured in
joules
what’s time measured in
seconds
how is heat transferred in solids
heat is transferred through conduction
how is heat transferred in liquid
heat is transferred in liquid through convection
how is heat transferred in space
heat is transferred in space through radiation
Equation for specific heat capacity
Change in thermal energy(J)= mass(m)×specific heat capacity(J/kg○C)× temperature change
What’s thermal energy
Thermal energy is the total energy requires to change the temperature of an object
What’s heat capacity
The specific heat capacity of a substance is the amount of energy required to raise the temperature of 1kg of the substance by 1C
Formula for theranl energy
Mass×specific heat capacity×temp change
Formula for heat capacity
Mass×specific heat capacity
What’s the law of energy?
Law of energy states that energy can be transferred usefully, stored or dissipated but it cannot be created or destroyed.
What’s an open system
If a system is open, energy can be transferred into or out of the system. For example, a beaker full of hot water is an open system because heat energy may transfer out of the beaker to the surroundings.
What is meant by SYSTEM
System mean an object or a group of object
Wnwrgy being dissipated meaning
Wasted
