Q. The electric field has been measured to be horizontal and to the right everywhere on the closed box. All over the left side of the box E1 = 120 V/m, and all over the right, slanting, side of the box E2 = 250 V/m. On the top the average field is E3 = 200 V/m, on the front and back the average field is E4 = 175 V/m, and on the bottom the average field is E5 = 220 V/m.

Q. The temperature of 1.5 kg of water is 34 °C. To cool the water, ice at 0 °C is added to it. The desired final temperature of the water is 11 °C. The latent heat of fusion for water is 33.5 ´ 104 J/kg, and the specific heat capacity of water is 4186 J/(kg·C°). Ignoring the container and any heat lost or gained to or from the surroundings, determine how much mass m of ice should be added.