Q1. The temperature of the glass surface of a 30 W light bulb is 75°C when the room temperature is 10°C. Estimate the temperature of a 150 W light bulb with a glass bulb the same size. Consider only radiation, and assume that 90% of energy is emitted as heat.
Q2. An ideal gas at 20 ^circ {rm C} consists of 2.8 times 10^ {22} atoms. 5.5 {rm J} of thermal energy are removed from the gas. What is a new temperature in ^circ {rm C}?