Spring and wave - physics

spring constant of a spring of 10g extended .25 m? what is the potential energy of the spring?

spring constant is F = -kx
PE is PE= 1/2kx^2

F = mass x gravity

Spring constant = k

k = F/x (just remember its  in a negative direction)
(10g x 9.8)/.25m = 98/.25 = 392 = -392

(1/2)*-392*.25^2 = 12.25 J (energy is scalar it is not pos or neg) *****remember sigfig******

Spring constant = -392
PE = 12 J

if there is an echo question asking how far away the object reflected is: distance = (velocity*times)/2

Wave types and properties… on powerpoint!!!!!!

mechanical waves  - sound waves… require a Medium (M-M)
electromagnetic - electricity- magnets - light and heat


phiberoptics - voice is turned to light for phones

compressional waves get close together and far apart, close and far… sound waves… transverse

longitudional - posing up and down and up and down… spring


calculating wavelength: c= 3x10^8
wavelength = c/frequency