Are amplitude and wavelength related? (will upvote)
yes
no

How does an observation about an object differ from an inference about that object

What are the north and south poles of a solenoid change with?

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.