energy Flashcards
what is kinetic energy
the energy stored in moving objects
equation for kinetic energy
0.5 x mass x speed squared
what is kinetic energy measured in
joules
unit for mass
kg
unit for speed
m/s
what type of objects have no kinetic energy
stationary objects
a tennis ball is travelling at 50 m/s
has kinetic energy of 75 j
what is mass of the ball
Ke = 1/2 m x v squared
m=2ke/v squared
m= 2(75)/50 squared
= 0.06
what is the energy change in a car running at a constant speed
chemical energy——> kinetic energy
what are we doing when stretching a spring
applying a force to change the length of a spring
what is applying a force called
work
what is elastic potential energy
the energy stored in a stretched spring
symbol for extension
lower case e
describe graph for extension of spring against force applied
straight line passing through 0
what happens if we apply to great of a force on a spring
the extension is no longer proportional to the force
what happens when a spring is stretched beyond the limit of proportionality
it will not return to original length if we remove force
