It’s most definitely answer C.
According to Einstein's Theory of Relativity, an object at rest experiences the time differently from an object moving: a moving clock would be slower than a resting clock.
Two objects experiencing the same acceleration, do experience the same time dilation, therefore a person on Earth's surface experiencing a gravitational acceleration of 9.8m/s² will feel the same effects of a person on a spaceship accelerating at 9.8m/s².
Hence, the correct answer is: <span>D) Acceleration in space and gravity on Earth have the same effects on objects.
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Speed = frequency * wavelength
So frequency = speed / wavelength
f = 330 / 0.25
f = 1320 Hz
2nd stone time = 13.0/9.8 = 1.33 seconds
distance = 0.5*9.8*1.33^2 = 8.67 meters
1st stone time = 1.33+1.5 = 2.83 seconds
distance = 0.5*9.8*2.83^2 = 39.24 meters
39.24-8.67 = 30.57 meters apart