Answer:
Δλ = 3*10⁻³ m.
Explanation:
- At any wave, there exists a fixed relationship between the speed of the wave, the wavelength, and the frequency, as follows:

where v is the speed, λ is the wavelength and f is the frequency.
- Rearranging terms, we can get λ from the other two parameters, as follows:

- Since v is constant for sound at 343 m/s, we can find the different wavelengths at different frequencies, as follows:


- The difference between both wavelengths, is just the difference between (3) and (4):

⇒ Δλ = 3*10⁻³ m.
Answer:
potential energy increases.
Explanation:
The potential energy between the two charged particles is given by
U = k Q q / r
If they are very far apart then r tends to infinity and the potential energy is zero.
If they come closer then the potential energy between the two charged particles increases.
Thus, the potential energy increases.
A big part of the reason that mirrors are seldom if ever used to generate
electricity is the simple fact that there is no way to generate electricity using
mirrors. They are as useless for the purpose as smoke is, although there are
those who have used both items simultaneously to create the impression that
they have succeeded in that attempt.