Answer:
NO
Explanation:
No, a machine cannot be 100% efficient. This is due to the movement of the moving parts siding against each other and causing friction. This friction is the one that creates heat and causes wear and tear between moving ports f the machine hence making the machine to decrease in efficiency with time
C. The object is not in motion, ruling out A. We are not adding mass in any way, nor does adding heat to object increase its mass, therefore also ruling out B. Finally, we are not changing the object's position in such a way that gives it a higher ability to do work, ruling out D.
Answer:
Explanation:
In order to answer this problem you have to know the depth of the column, we say R, this information is important because allows you to compute some harmonic of the tube. With this information you can compute the depth of the colum of air, by taking tino account that the new depth is R-L.
To find the fundamental mode you use:

n: mode of the sound
vs: sound speed
L: length of the column of air in the tube.
A) The fundamental mode id obtained for n=1:

B) For the 3rd harmonic you have:

C) For the 2nd harmonic:

The mass of the astronaut is still 65 kilograms. Mass is constant or doesn't change no matter where you are.