Answer:
Force of <u>1</u><u>0</u><u>0</u><u> </u><u>N</u><u> </u>will be needed.
Explanation:

g is acceleration due to gravity
m is the mass

Answer:
The speed of the laser light in the cable, 
Explanation:
It is given that,
Wavelength of Argon laser, 
Refractive index, n = 1.46
Let
is the speed of the laser light in the cable. The speed of light in a medium is given by :



or

So, the speed of the laser light is
. Hence, this is the required solution.