The Richter Scale<span> is not commonly </span>used<span> anymore, except for small </span>earthquakes<span>recorded locally, for which ML and Mblg are the only </span>magnitudes<span> that can be measured. For all other </span>earthquakes<span>, the </span>moment magnitude scale<span> is a more accurate measure of the </span>earthquake<span> size.</span>
The answer will be: A) Metal washers.
(a) The efficiency of an engine is defined as the ratio between the work done by the engine and the heat it takes in:

The engine in this problem does a work of

and it takes in

of heat, therefore its efficiency is

(b) The heat taken by the machine is 4000 J; of this amount of heat, only 1100 J are converted into useful work. This means that the rest of the heat is wasted. Therefore, the wasted heat is the difference between the heat in input and the work done by the engine:
Explanation:
Incident light makes an electron oscillate. The electrons emit light or absorb the light, collide with other electrons, thereby converting light energy to more internal energy. and convert it to heat.
Light wave of a given frequency is incident on a material with electrons having the same vibrational frequencies, then electrons absorb the energy of the light wave and transform it into vibrational motion.