Answer:
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.
Cheers!
I believe the answer is a: cells.
George used the spring scale. For example: Using a spring scale on an elevator. As you go either up a floor or down a floor the gravity will change the outcome of the scale's measurements.
Answer:
The resistance of the silicon has to be 80 Ω and the iron must be 1120 Ω
Explanation:
Lets take
Temperature coefficients of resistivities or iron = 
Temperature coefficients of resistivities or silicon = 
The resistance of the iron increases a little as the temperature rises
The resistance of the silicon decreases a lot as the temp rises.
So we want the iron to be most of the resistance and have its increase in resistance exactly equal to the drop in resistance of the silicon.
Since the drop in the silicon is 15 times the rise in the iron ( 75 / 5 ) you want the iron to have 15 time the resistance of the silicon. And the total resistance has to be 1200Ω
1200/15 = 80
So
The resistance of the silicon has to be 80 Ω and the iron must be 1120 Ω
The boat could easily pass through me ( particle of water) because the forces of attraction between the particles and the density is less than the particles of a solid.