Which type of wave does not require a medium to travel through

According to newtons universal law of gravitation, which would change the parh of the ball so it traces out widest curved path possible?

What is special about a dc circuit ?

6–43 a food department is kept at 2128c by a refrigerator in an environment at 308c. the total heat gain to the food department is estimated to be 3300 kj/h and the heat rejection in the condenser is 4800 kj/h. determine the power input to the compressor, in kw and the cop of the refrigerator.