An inventor develops a stationary cycling device by which an individual,while pedaling,can convert all of the energy expended into heat for warming water.What minimum power must be generated if 300 g water (enough for 1 cup of coffee)is to be heated in 10 min from 20 $\degree$C to 95 $\degree$C? (1 cal = 4.186 J,the specific heat of water is 4 186 J/kg*$\degree$C)
A)9 400 W
B)590 W
C)160 W
D)31 W

Question

Quizplus · Accepted Answer

The energy required to heat the water can be calculated using the formula Q = mcΔT. Here, m = 0.3 kg, c = 4186 J/kg°C, and ΔT = 95°C - 20°C = 75°C. Thus, Q = 0.3 * 4186 * 75 = 94185 J. The power required is P = Q/t, where t = 10 min = 600 s. So, P = 94185 J / 600 s = 156.975 W, which is approximately 160 W.

An Inventor Develops a Stationary Cycling Device by Which an Individual,while