How is biodiversity related to biosphere?

The frequency of the fundamental of the guitar string is 320 hz. at what speed v do waves move along that string?

Aresistor with an unknown resistance is connected in parallel to a 9 ω resistor. when both resistors are connected in parallel to an emf source of 21 v, the current through the unknown resistor is measured with an ammeter to be 4 a. what is the resistance of the unknown resistor? answer in units of ω.

How does changing the frequency affect the energy of the wave?