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?

Apulley system is used to lift a 2,000 newton engine up a distance of 3 meters. the operator must apply a force of 250 newtons to the chain of the pulley system to lift the motor. to lift the engine 3 meters, the operator must pull a total of 30 meters of chain through the pulley system. what is the value of di?

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.

The great sandini is a 60.0-kg circus performer who is shot from a cannon (actually a spring gun). you don’t find many men of his caliber, so you him design a new gun. this new gun has a very large spring with a very small mass and a force constant of 1100 n/m that he will compress with a force of 4400 n. the inside of the gun barrel is coated with teflon, so the average friction force will be only 40.0 n during the 4.00 m he moves in the barrel. at what speed will he emerge from the end of the barrel, 2.50 m above his initial rest position?