. Iron at 30 °C is put into thermal contact with an unknown material at 60 °C of equal mass. The equilibrium temperature is measured to be 50 °C. Which of the materials below could be the identity of the unknown material?

Atank has a shape of a cone with a radius at the top of 2 m and a height of 5 m. the tank also has a 1 m spout at the top of the tank. the tank is filled with water up to a height of 2 m. find the work needed to pump all the water out the top of the spout. (use 9.8 m/s2 for g and the fact that the density of water is 1000 kg/m3.)