An alternating current having peak value 1. 4 a is used to heat a metal wire. To produce the same heating effect in same metal wire, a constant current i can be used, where i is nearly.

Let f(x) = x4- 8x2 . find the relativeextrema of this function using the second derivative test.

A100-watt light bulb illuminates a solar cell. the electricity from the solar cell operates a water pump that delivers 1 watt of power. what is the efficiency of the system?

6–48 bananas are to be cooled from 24 to 138c at a rate of 215 kg/h by a refrigeration system. the power input to the refrigerator is 1.4 kw. determine the rate of cooling, in kj/ min, and the cop of the refrigerator. the specific heat of banana above freezing is 3.35 kj/kg·8c.