None of the choices is correct.
Satellite communication is quite effective using either analog OR digital transmission.
Sound can't be used for satellite communication at all. (There's no medium to carry the sound to or from the satellite, and if there were, then the round-trip up and down through a geostationary satellite would take at least a minute at the sea-level speed of sound.)
Cellular devices can work but aren't required.
Is there any chemical names listed ?
Can you give us a picture or something please!!
Answer:
D, using a spring scale to exert a force on the block. Measure the acceleration of the block and the applied force
Explanation:
For this you would use the net force equation acceleration=net force * mass however you will want to isolate mass so it would be acceleration/ net force to get mass. Then process of elimination comes to play.