To keep yourself warm in the winter, you heat a solid metal ball and place it on a stand in the center of your room. The ball has a radius of 17.0 cm and an emissivity of 0.830. If your room has a temperature of 15°C, what is the net power radiated by the ball initially, when the ball's temperature is 200°C?

The urban heat island effect is often strongest at night when temperatures would typically drop.  What does this indicate about energy transfer and the material used in the building? (a) The material in buildings releases more energy at night than it absorbs during the day (b) The material in buildings absorbs a lot of energy during the day and when it gets colder at night the energy is released back into the cooler air. (c) The material in buildings absorbs energy during the day and releases it because the temperature of the buildings is lower than the cooler air (d) The material in buildings releases a lot of energy into the hot air during the day so at night all of the energy is still there

Question 4. A 5.0 kg block of aluminium is heated from 20°C to 90°C at atmospheric pressure. Find (a) the work done by the aluminium, (b) the amount of energy transferred to it by heat, and (c) the increase in internal energy.

Suppose 9.30 x 105 J of energy are transferred to 2.00 kg of ice at 0°C. (a) Calculate the energy required to melt all the ice into liquid water. (b) How much energy remains to raise the temperature of the liquid water? (c)Determine the final temperature of the liquid water in Celsius.