I don't like the wording of any of the choices on the list.
SONAR generates a short pulse of sound, like a 'peep' or a 'ping',
focused in one direction. If there's a solid object in that direction,
then some of the sound that hits it gets reflected back, toward the
source. The source listens to hear if any of the sound that it sent
out returns to it. If it hears its own 'ping' come back, it measures
the time it took for the sound to go out and come back. That tells
the SONAR equipment that there IS a solid object in that direction,
and also HOW FAR away it is.
RADAR works exactly the same way, except RADAR uses radio waves.
Answer:
demand (an amount) as a price for a service rendered or goods supplied.
Explanation:
to enter or record as an obligation against a person or his account. to accuse or impute a fault to (a person, etc), as formally in a court of law. to command; place a burden upon or assign responsibility toI was charged to take the message to headquarters.
Ammonia because it doesn't have nitrogen
Answer:
Reflection is when light bounces off an object, while refraction is when light bends while passing through an object.
Around the nucleus or in the shell of the atom. Hope this makes sense.
