This is caused my a magic illusion and when you stand at a certain angle in themirror it changes your image
Answer:
v = 19.2 m/s
Explanation:
In order to find the speed of the string you use the following formula:
(1)
f: frequency of the string = 80.0Hz
v: speed of the wave = ?
L: length of the string = 12.0cm = 0.12m
The length of the string coincides with the wavelength of the wave for the fundamental mode.
Then, you solve for v in the equation (1), and replace the values of the other parameters:
The speed of the wave is 19.2 m/s
Set up a proportion
1 mile/1.6 km = 20,000miles/x
Cross Multiply
x = (20,000) * (1.6)
x = 32,000 kilometers
Energy transfer by waves: two primary modes = (electromagnetic waves, compression/transverse waves propagating through a medium)
1) electromagnetic waves:
Using a particle model for the wave (photons for light), energy transfer is similar to that by discrete moving object -- particles carry the energy from one place to another in the absence of a medium.
Energy delivery: discrete moving object uses inertia and momentum to transfer the energy from itself to the target. Photons are massless, so the energy delivery mechanism must be different.
2) compression/transverse waves propagating through a medium:
Energy passes through the medium with little to no net flow of the medium itself. In transverse water waves, when the energy wave passes by, to first order, the water particles move in vertical circular paths. This is different from energy transfer by a moving object in that the moving object must displace itself to the target position in order to deliver the energy -- resulting in a net flow of object material.
