The freezing point ..... :)
Answer:

Explanation:
Assuming uniform spread of sound with no significant reflections or absorption. We know that sound intensity varies
where r is the distance
Since intensity is given then when at 3 m


Since we have the constant then at 4m
Intensity, 
Answer:

Explanation:
As we know that the that the Astronaut dropped a stone on the surface of the planet takes 0.420 s to fall a distance of d = 1.90 m
so we will have



now we know that the acceleration due to gravity is given as

so we will have


The answer is C. Electrical;mechanical