Forces and Energy Flashcards
what are the 8 different energy sources?
- kinetic energy
- thermal
- chemical
- gravitational potential
- elastic potential
- electrostatic
- magnetic
- nuclear
how can energy be transferred between stores?
- mechanically
- electrically
- heating
- radiation
what happens when there is an energy change in a closed system?
there is no net change to the total energy in that system
how do you calculate work done?
E= F X d workdone= force X distance
what are energy joules (J) equal to?
work done joules
what equation is used to calculate gravitational potential energy when an object is raised above ground?
GPE= m X g X h
how do you calculate kinetic energy?
KE= 0.5 X m X v2
what happens when a system changes energy?
- energy get dissipates
- thermal energy
- wasteful, efficiency reduced
what is the definition of power?
- the rate at which energy is transferred
- how much work is being done every second
whats the equation for power?
P= E / t power(W)= workdone(J) / time taken(S)
what is one watt equal to?
1joule/ second
what is the efficiency equation?
total energy supplies to device
how can objects react with and without forces?
- contact forces- friction
- non contact forces- gravity, magnetic fields
what is a vector?
has size and direction
-force
what is a scaler?
only has size
-mass
