An astronaut is moving in space when a big explosion occurs about 50 meters behind him. How will the astronaut come to know about the explosion? Choose:--
From the sound of the explosion
From the light due to the explosion
From light and sound due to the explosion
From the vibrations due to the explosion

The correct answer is B.

The astronaut will know due to the light from the explosion.

Explanation:

Sound and vibrations require a medium such as air to travel through. Space, there is no air. Only a vacuum. So sound and vibrations are unable to travel. Light requires no medium to travel. It can go through a vacuum.  

Therefore the Astronaut will see a bright flash of light as it travels from the explosion to outer space. It is also important to note that light can travel very far because nothing else interacts with its wave particles and as such, it cannot be impeded.

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the body's situation won't change the forces are equal opposit and on the same body