Questions 1. Explain why the experiments can give only approximate values for the specific latent heat of fusion of water and the specific latent heat of vaporisation of water?

2. An electric kettle which is rated at 2250 W contains 0.8 kg of water. It takes 150 s to heat the water from 10°C to 100°C. The specific heat capacity of water is 4200 J kg−1 K−1.
a Calculate:
i the heat energy produced by the kettle in this time

ii the heat taken in by the water in this time.

b Suggest two reasons for the difference between these two quantities.

Glass is transparent to visibile light under normal conditions; however, at extremely high intensities, glass will absorb most of the light incident upon it. this works through a process known as multiphoton absorption. in this process, several photons are absorbed at the same time. if very intense light whose photons carry 2ev of energy is shined onto a material with a band gap of 4ev, that light can be absorbed through two-photon absorption, because two photons have the right amount of energy to bridge the band gap. what is the minimum number of photons of 800-nm light that are needed to equal or exceed the band gap of fused silica glass

The bar of prob. 5/82 is repeated here. the ends of the 0.4-m bar remain in contact with their re- spective support surfaces. end b has a velocity of 0.5 m/s and an acceleration of 0.3 m/s2 in the di- rections shown. determine the angular accelera- tion of the bar and the acceleration of end a.

How does the entropy of steam compare to the entropy of ice?