Because its a vacuum, there's no air resistance, they will fall at same time
Applying gravity acceleration rule g=9.8m/s which is taken as 10m/s sometimes.
Answer: A
Causing air molecules to vibrate
Explanation:
Sound is made by vibrations. And it is an energy. When any object vibrates, it causes movement in the air particles. These particles bump into the particles close to them, which makes them vibrate too causing them to bump into more air particles. This movement, called sound waves, keeps going until they run out of energy.
Answer:
Frequency, 
Explanation:
Given that,
The wavelength of the x-rays, 
We need to find the frequency of an x-ray. All electromagnetic wave travel with a speed of light. It is given by the formula as :
f is the frequency
So, the frequency of an x-ray is 
. Hence, this is the required solution.
