Answer:
The wavelength of light is 
Explanation:
Given that,
Angle = 13.1°
Number of slits = 5000
We need to calculate the wavelength of light
Diffraction of first order is defined as,
.....(I)
The separation of the slits



Now put the value in equation (I)

Here, n = 1

Hence, The wavelength of light is 
Answer:
The length of the object would shrink to zero which is not possible.
Explanation:
A rocket or any body cannot reach the speed of light because according to theory of relativity the and the Lorentz factor the length of the object would shrink to zero and the time dilation for that body would be infinite.
The Lorentz factor is given as:

where:
v = speed of the moving object
c = speed of light
It’s a force which acts on an object without coming physically in contract with it.
<em>500 sec</em>
<em>8 min 20 sec</em>
<em>Hi there !</em>
<em />
<em>8 m ................ 1 s </em>
<em>4000 m ........ x s</em>
<em>x = 4000m×1s/8m = 500 sec = 8 min 20 sec</em>
<em />
<em>Good luck ! </em>
Using current technology, useful parallax measurements can only be found for stars up to about 340 light years (100 parsecs) away.