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.How much mechanical energy is required to increase the temperature of 200 g of water (enough for 1 cup of coffee)from 18°C to 94°C? (1 cal = 4.186 J,the specific heat of water is 4 186 J/kg⋅°C)
A)6.4E+4 J
B)3.2E+4 J
C)1.6E+4 J
D)1.0E+3 J
E)1.5E+1 J

Question

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.How much mechanical energy is required to increase the temperature of 200 g of water (enough for 1 cup of coffee)from 18°C to 94°C? (1 cal = 4.186 J,the specific heat of water is 4 186 J/kg⋅°C)​
A)6.4E+4 J
B)3.2E+4 J
C)1.6E+4 J
D)1.0E+3 J
E)​1.5E+1 J

Quizplus · Accepted Answer

The energy required is calculated using the formula: Q = mcΔT. Here, m = 0.2 kg, c = 4186 J/kg°C, and ΔT = 94°C - 18°C = 76°C. So, Q = 0.2 * 4186 * 76 = 63665.6 J, which is approximately 6.4E+4 J.

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