1. The radius of the Sun is 7 × 108 m and the radius of the Earth's orbit is 1.5 × 1011 m. The energy flux leaving the Sun's surface is 6.4 × 107 W/m2. What is the flux of solar energy at the distance of the Earth?
2. Why is a teapot shiny silver, rather than black? Why is your car radiator black?