How does the force of friction for a sliding object vary with the area of contact?

Asmall aircraft, on a heading of 225°, is cruising at 150 km/h. it is encountering a wind blowing from a bearing of 315° at 35 km/h. determine the aircraft’s ground velocity.

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.

Contains chemical energy. a. heat b. light c. natural gas