Write an essay about the Electromagnetic spectrum and its many uses in real life practices. Answer these questions in the essay: 1. What types of waves make up the electromagnetic spectrum? 2. How are electromagnetic waves used for communication?
3. How are electromagnetic waves used in the military?
4. How are electromagnetic waves used in the medical field?

work: w = fd (given)

work done by chet   =50*1 = 50 j

work done by mika =40*2 = 80 j

work done by sara =30*1.5 = 45 j

work done by bill =60*0.5 = 30 j

students in order from the greatest amount of work done to the least is mika> chet> sara> bill

hence option (b) is correct.

firearm identification is the process of analyzing the bullets and cartridge cases left at a crime scene to determine if they came from a particular firearm. marks on the bullets and cartridges may be common to every firearm of that type. these are called class characteristics.