Answer:
The conditions necessary for hearing the echo. The distance between the sound source and the reflecting surface must not be less than 17 metres where the time period between hearing the original sound and its echo should not be less than 0.1 of a second.
Answer: assuming that the billiard balls are of identical weight the impacted billiard ball will move forward at around 0.5m/s (not considering energy conservation). The ball impacting the 2nd one would stop because most of its Kinetic energy would have been transferred into the not moving ball.
Explanation: hope this helps!
C. 70 inches is the answer
Energy transfer is when a energy transfers from a body/object to another.
Energy transformation is when energy is transformed into another form.
There is an energy transfer from the heat lamp to the baby zebra.