A company is developing a system which can heat up and melt ice on roads in the winter. This system is called 'energy storage'.
During the summer, the black surface of the road will heat up in the sunshine.
This energy will be stored in a large amount of soil deep under the road surface.
Pipes will run through the soil. In winter, cold water entering the pipes will be warmed and
brought to the surface to melt ice.
The system could work well because the road surface is black.
Suggest why

Write a full page that sumerizes thermodynamics it’s from the website visionlearnig

Consider a double atwood machine constructed as follows: a mass 4m is suspended from a string that passes over a massless pulley on frictionless bearings. the other end of this string supports a second similar pulley, over which passes a second string supporting a mass of 3m at one end and m at the other. using two suitable generalized coordinates, set up the lagrangian and use the lagrange equations to find the acceleration of the mass 4m when the system is released. explain why the top pulley rotates even though it carries equal weights on each side.

What is friction? how does it affect the motion of an object?