<h2>
Answer: can see</h2>
Explanation:
The portion visible by the human eye of the electromagnetic spectrum is between 380 nm (violet-blue) and 780 nm (red) approximately. Which means this part of the spectrum is located between ultraviolet light and infrared light.
Note the fact only part of the whole electromagnetic spectrum is visible to humans is because the receptors in our eyes are only sensitive to these wavelengths.
Therefore:
<h2>The visible spectrum refers to the portion of the electromagnetic spectrum that <u>we </u><u>
can see</u></h2>
Answer:

Explanation:
Given:
mass of ice melted, 
time taken by the ice to melt, 
latent heat of the ice, 
Now the heat rejected by the Carnot engine:



Since we have boiling water as hot reservoir so:

The cold reservoir is ice, so:

Now the efficiency:



Now form the law of energy conservation:
Heat supplied:

where:
heat supplied to the engine




Now the work done:



Answer:
A.
B.s=397.6 m
Explanation:
Given that
speed u= 284.4 m/s
time t = 1.4 s
here he want to reduce the velocity from 284.4 m/s to 0 m/s.
So the final speed v= 0 m/s
We know that
v= u + at
So now by putting the values
0 = 284.4 -a x 1.4 (here we take negative sign because this is the case of de acceleration)

So the acceleration while stopping will be
.
Lets take distance travel before come top rest is s
We know that


s=397.6 m
So the distance travel while stopping is 397.6 m.