When you hear an echo you are hearing a the original sound wave
a. refraction
b. resonance
c. reduction
d. reflection

reflection

Choice D is correct

Explanation:

An echo is simply a reflection of the original sound wave which arrives at the listener with a delay after the original sound.  Sound waves can be reflected, that is bouncing off objects in the same manner a solid object can bounce off the ground. The echo sounds entirely the same as the original sound but the direction of the sound is altered.

2b2t

explanation:

2b2t

the small 0.38-kg slider is known to move from position a to position b along the vertical-plane slot. determine (a) the work done on the body by its weight and (b) the work done on the body by the spring. the distance r = 0.70 m, the spring modulus k = 154 n/m, and the unstretched length of the spring is 0.53 m

explanation:

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