A beaker contains 0.500 kg of water at a temperature of 3.0 °C. The beaker is heated, and the
internal energy of the water increases by 21.0 kJ.
The specific heat capacity of water is 4200 J / (kg °C).
What is the temperature of the water after it has been heated?

The temperature of the water after it has been heated is 13°C

Explanation:

Heat capacity H is expressed as shown :

H = mc∆t

H is the internal energy of the water

m is the mass of the water

c is the specific heat capacity of the water

∆t is the change temperature

Given H = 21kJ = 21,000Joules

m = 0.500kg

c = 4200 J / (kg °C).

∆t = t2-t1

t2 is the final temperature

t1 is the initial temperature = 3°C

Substituting the parameters;

21000 = 0.5(4200)(t2- 3)

21000 = 2100(t2-3)

21000 = 2100t2 - 6300

2100t2 = 21000+6300

2100t2 = 27300

t2= 27300/2100

t2 = 13°C

-first use of geothermal energy occurred more than 10,000 years ago in north america by american paleo-indians

-the first industrial use of geothermal energy began near pisa, italy in late 18th century

-in 1904, italian scientist piero ginori conti invented the first geothermal electric power plant in which steam was used to generate the power

-with the above experiment, the first geothermal plant in usa started in 1922 with a capacity of 250 kilowatts

-however, in 1946 first ground-source geothermal heat pump installed at commonwealth building in portland, oregon

-during the 1960’s, pacific gas and electric began operation of first large scale geothermal power plant in san francisco, producing 11 megawatts

-in 1973, when oil crisis began many countries began looking for renewable energy sources and by 1980’s geothermal heat pumps (ghp) started gaining popularity in order to reduce heating and cooling costs

-as effect of climate change started showing results, governments of various countries joined hands to fight against it, for which kyoto protocol was signed in japan in 1997, laid out emission targets for rich countries and required that they transfer funds and technology to developing countries, 184 countries have ratified it

hope this