Forces and Energy Ch4 Flashcards
what is the equation for work
force x distance
what are the two types of energies
- energy
- potential
what are the enegies
A) kinetic- movement: all particles move and have energy
B) chemical: chemical reactions - usually exothermic
C) thermal/ heat: waste product of most energy
D) nuclear: radiation from nuclear decay
E) magnetic: repulsion or attraction by magnetic material
what are the potential energies
A) electrostatic (voltage): energy only released when a circuit is formed
B) elastic: energy only released when stretched (or compressed) object is relieved
C) gravitational: energy only present when object is lifted
what is the law of conservation of energy
energy cannot be created or destroyed
what is the equation for gravitational potential energy
gravitational potential energy= mass x gravity x height
GPE=mgh
what is the equation for kinetic energy
kinetic energy = 1/2 mass x velocity2
KE=1/2mv2
what is the equation for efficiency
useful work done/ total energy impute
what is the equation for power
work done or energy transferred/ time taken
what is power
power is work done (or energy transferred) in a given amount of time
eg. 1 watt= 1J/ 1 second
what is the equation for useful work impute
force x speed
what are the units for power, work and energy
power= watts
work= J
energy= J
