Question1
A planet of mass 8 × 1024 kg is at location ‹ −3 × 1011, 6 × 1011, 0 › m. A star of mass 9 × 1030 kg is at location ‹ 7 × 1011, −6 × 1011, 0 › m. What is the force exerted on the planet by the star? (It will probably be helpful to illustrate a diagram, including the relevant vectors.)
Question2
A person eats a dessert that contains 200 Calories. (This "Calorie" unit, with a capital C, is the one used by nutritionists; 1 Calorie = 4186 J. The skin temperature of the person is 36 °C and that of her environment is 20 °C. The emissivity of her skin is 0.71 and its surface area is 1.3 m2. How many hours would it take her to release a net radiant energy from her body that is identical to energy contained in this dessert?