The Mechanical Equivalent of Heat Is 1 Cal = 4 $\degree$

Multiple Choice

The mechanical equivalent of heat is 1 cal = 4.18 J. The specific heat of water is 1 cal/g·K. An electric immersion water heater, rated at 400 W, should heat a liter of water from 10 $\degree$ C to 30 $\degree$ C in about:

A) 3.5 min
B) 1 min
C) 15 min
D) 45 min
E) 15 s