A 25-g string is stretched with a tension of 43 N between two fixed points 12 m apart. What is the frequency of the second harmonic?

The frequency of the second harmonic () is 11.97 Hz.

Explanation:

Given;

mass of the string, m = 25 g = 0.025kg

tension on the string, T = 43 N

length of the string, L = 12 m

The speed of wave on the string is given as;

where;

μ is mass per unit length = 0.025 / 12 = 0.002083 kg/m

The wavelength of the first harmonic wave is given as;

The frequency of the first harmonic is given as;

The wavelength of the second harmonic wave is given as;

The frequency of the second harmonic is given as;

Therefore, the frequency of the second harmonic () is 11.97 Hz.

answer: the exterior temperature of commercial jet planes as they leave the stratosphere and return to the ground increases steadily.

explanation:

the lower most layer of atmosphere is troposphere which extends from 0 to 12 km above the surface of the earth. the temperature initially decreases as distance is increased from the earth's surface. commercial jets fly in lower part of the stratosphere. the stratosphere extends upto 50 km. the temperature in stratosphere starts rising again due to presence of ozone which traps the uv rays.

thus, when the planes leave the stratosphere and return to the ground, the exterior temperature increases steadily.