A115-volt electrical heater is used to warm 0.3 m3/s of air at 100 kpa and 15°c to 100 kpa and 30°c. how much current in amperes must be supplied to this heater? the gas constant of air is 0.287 kpa·m3/kg·k. the constant pressure specific heat of air at room temperature is cp = 1.005 kj/kg·°c.

Ariver flows from north to south at 8 km/h. a boat is to cross this river from west to east at a speed of 20 km/h (speed of the boat with respect to the earth/ground). at what angle (in degrees) must the boat be pointed upstream such that it will proceed directly across the river (hint: find the speed of the boat with respect to water/river)? a 288 b. 21.8 c. 326 d. 30.2