From the Hooke's law , the extension force of an elastic material is directly proportional to the extension.
That is, F = k e, where F is the force , k is the constant and e is the extension
F = 10 × 10 = 100 N
e = 1mm or 0.001 m
Hence, k = F/e
= 100 N/ 0.001
= 100000 N/m or 100 N/mm
Answer:

Explanation:
As we know that


also we know that

it is given as


also we can find the magnitude of two vectors as


similarly we have


now we know the formula of dot product as




Answer:
A lens
Explanation:
A lens forms images when light passes Through it bending the rays of in the process.A phenomena called refraction and the speed of light changes in the process because it enters a medium since it's wavelength is reduced.
Answer:
The amount of mass that needs to be converted to release that amount of energy is 
Explanation:
From Albert Einstein's Energy equation, we can understand that mass can get converted to energy, using the formula

where
= change in mass
c = speed of light = 
Making m the subject of the formula, we can find the change in mass to be

There fore, the amount of mass that needs to be converted to release that amount of energy is 1.122 X 10 ^-7 kg