Science Assessment ~ Topics ~ Energy: Forms, Transformation, Transfer, and Conservation ~ Item RG195001 ~ Student Performance

A submarine uses sonar to detect objects underwater. Sonar is a process by which a sender emits brief sounds. When the sound hits an object, a portion of the sound returns to the submarine as an echo. The sonar unit uses the length of time it took the sound to make the round trip to determine how far away the object is.

Does the sound from the sender transfer energy to the object in the figure above? Why or why not?

Yes, sound pushes water molecules that are near the sender to the object and the force that those water molecules exerts on the object transfers energy to that object.
Yes, sound transfers energy from one water molecule to the next when the molecules collide until the energy reaches the object, but the water molecules do not travel from the sender to the object.
No, sound transfers forces from one water molecule to the next, but does not transfer energy.
No, since the object reflects some of the sound back to the receiver, no energy was transferred to the object.

Distribution of responses
Answer Choice		Overall	Grades			Gender		Primary Language
		n = 2975	4–5 n = 0	6–8 n = 1564	9–12 n = 1411	Male n = 1382	Female n = 1517	English n = 2681	Other n = 205
A.	Yes, sound pushes water molecules that are near the sender to the object and the force that those water molecules exerts on the object transfers energy to that object.	33%	N/A	34%	32%	32%	34%	33%	36%
B.	Yes, sound transfers energy from one water molecule to the next when the molecules collide until the energy reaches the object, but the water molecules do not travel from the sender to the object.	39%	N/A	38%	39%	40%	38%	39%	32%
C.	No, sound transfers forces from one water molecule to the next, but does not transfer energy.	14%	N/A	14%	15%	15%	14%	14%	18%
D.	No, since the object reflects some of the sound back to the receiver, no energy was transferred to the object.	14%	N/A	14%	14%	13%	14%	14%	14%

Science Assessment

Item RG195001: Sound transfers energy from a sender to an object by a series of molecular collisions, but the molecules do not travel from the sender to the object.