Two 50 g metal blocks, one made of lead and the other of iron, are heated to 100°C. They are placed in identical calorimeters, each with 100 g of water at a starting temperature of 20°C. Which calorimeter will have the higher temperature at thermal equilibrium: the one with lead or the one with iron? Explain your answer.

The first law of thermodynamics states that heat added to a system is neither created nor destroyed but is transformed ⇒ as it changes into other forms of energy.

Two masses are connected by a rope that hangs over a pulley as shown below. the pulley is a uniform cylinder of radius 푅=0.381meters and mass 푀=3.1푘푔. initially 푚"is on the ground and 푚#rests 2.5 meters above the ground. if the system is released, use conservation of energy to determine the speed of 푚#just before it strikes the ground. assume the pulley bearing is frictionless.

If you held a stone over the mouth of a well and then let it go , what would happen to the stone? explain your answer.