Your house has a voltage of 120V. You want to estimate how much energy (in Joules) you use one morning. You wake up at 7am and leave your place at 9 am. The appliances turned on in your kitchen at breakfast time are:

Question

•One hot plate: runs for 10 minutes, 6 A
•Refrigerator: 500W when the compressor is running (i.e. when it does the humming sound for 2 minutes every hour)
•10 light bulbs, used for two hours, 100W each.
•You use 150L of warm water (38ºC) heated up by the hot water tank from a temperature of 15ºC(150 L = 1.5 m^3). Warming up 1 litre of water by one degree takes 4186 J

Calculate the energy use of each appliance

Answer 1

hot plate=120*6*10/60
refer= 500(2/60)*2
lights- 10*100*2
water= 150*(38-15)*4186
add them up.
btw: not that it is needed, but 1m^3=1000L, the conversion given 150L=1.5m^3 is very wrong. 1.5m^3=1500L