Energy can not be created or destroyed but can change from one form to another.
example: as a roller coaster cart loses height the more speed it gains, the potential energy is transferred into kenetic energy
Beginning around 5,500 years ago, the Sumerians built cities along the rivers in Lower Mesopotamia, specialized, cooperated, and made many advances in technology. The wheel, plow, and writing (a system which we call cuneiform) are examples of their achievements.
Answer:
According to Hook's law, we know,
strain/stress =Constant
Explanation: So, the ratio between stress and strain is always constant.
So, if stress is increased, then strain changes in that way so that this ratio always remains constant.
Complete Question
At what angle should the axes of two Polaroids be placed so as to reduce the intensity of the incident unpolarized light to 1/5.
Answer:
The angle is
Explanation:
From the question we are told that
The light emerging from second Polaroid is 1/5 the unpolarized
Generally the intensity of light emerging from the first Polaroid is mathematically represented as

Generally from the Malus law the intensity of light emerging from the second Polaroid is mathematically represented

=> 
=> 
From the question


=> ![\theta = cos ^{-1} [\sqrt{\frac{2}{5}} ]](https://tex.z-dn.net/?f=%5Ctheta%20%3D%20%20%20cos%20%5E%7B-1%7D%20%5B%5Csqrt%7B%5Cfrac%7B2%7D%7B5%7D%7D%20%20%5D)
=> 