Q. A 35 g ice cube floats in 190 g of water in a 100 g copper cup; all are at a temperature of 0°C. A piece of lead at 98°C is dropped into the cup, and the final equilibrium temperature is 12°C. What is the mass of the lead? (The heat of fusion and specific heat of water are 3.33 105 J/kg and 4,186 J/kg · °C, respectively. The specific heat of lead and copper are 128 and 357 J/kg · °C, respectively.)
Q. Driving in your car with a constant speed of 12 {rm m}/{rm s}, you encounter a bump in the road that has a circular cross-section. If the radius of curvature of the bump is 35 {rm m}, find the apparent weight of a 69 person in your car as you pass over the top of the bump.