Q1. A jeweler working with a heated 43 gram gold ring must lower the ring's temperature t make it safe to handle. If the ring is initially at 94 degrees Celsius, what mass of water at 22 degrees Celsius is necessary to lower the ring's temperature to 38 degrees Celsius?

Q2. A 1800 kg car moving at an initial speed of 35 m/s along the horizontal road skids to a stop in 58 m. (Note: When stopping without skidding and using conventional brakes, 100 percent of the kinetic energy is dissipated by friction within the brakes. With regenerative braking, such as that used in hybrid vehicles, only 75 percent of the kinetic energy is dissipated.) (a) Find out the energy dissipated by friction. (b) Find out the coefficient of kinetic friction between the tires and road.