Answer:
Grow up man, this is completely based on your curriculum, we would need your book to answer, and this has to be done by you.
Answer:
light doesn't need a medium through which to travel because the speed of light is experimentally constant
For fundamental frequency of a string to occur, the length of the string has to be half the wavelength. That is,
1/2y = L, where L = length of the string, y = wavelength.
Therefore,
y = 2L = 2*0.75 =1.5 m
Additionally,
y = v/f Where v = wave speed, and f = ferquncy
Then,
v = y*f = 1.5*220 = 330 m/s
Answer: Erosion or water level rising
Explanation: Erosion happens when water goes against a rock and breaks it down little by little so these mountains may have once been above water but became eroded. Also, people might’ve added so much pollution into the ocean that the water level rose or there was an increase in the population of large animals. Sorry for my very long answer lol
Answer:
Thus, if field were sampled at same distance, the field due to short wire is greater than field due to long wire.
Explanation:
The magnetic field, B of long straight wire can be obtained by applying ampere's law

I is here current, and r's the distance from the wire to the field of measurement.
The magnetic field is obviously directly proportional to the current wire. From this expression.
As the resistance of the long cable is proportional to the cable length, the short cable becomes less resilient than the long cable, so going through the short cable (where filled with the same material) is a bigger amount of currents. If the field is measured at the same time, the field is therefore larger than the long wire because of the short wire.