Why does the interior of a car parked in the sun become hot?

78 Heat produced on burning 5gm of a fuel raises the temperature of 1 kg of H₂O from 20^oC – 60^oC. If the specific heat of H₂O is 4.2J/g^oC, calculate the calorific value of the fuel? 79 Explain greenhouse effect. 81 What is solar constant? 82 What radiations are converted to electricity in a solar cell? What are they used?