In a game of football outdoors on a cold day, a player will begin to feel exhausted after using approximately 8.0 * 105 J of internal energy. (a) One player, dressed too lightly for the weather, has to leave the game after losing 6.7 * 105 J of heat. How much work has he done? (b) Another player, wearing clothes that offer better protection against heat loss, is able to remain in the game long enough to do 2.6 * 105 J of work. What is the magnitude of the heat that he has lost?

a) How much work has he done = dW = 1.3 * 105 J

b) What is the magnitude of the heat that he has lost = dQ = - 5.4 * 105 J

Step-by-step explanation:

From the first law of thermodynamics; dQ = dU + dW dU = - 8.0 * 105 J dQ = - 6.7 * 105 J

Hence, work done dW = dQ - dU

dW = - 6.7 * 105 J - (-8.0 * 105 J)

dW = 1.3 * 105 J is the work done by the player

for heat lost; from dQ = dW + dU dU = - 8.0 * 105 J and dW = 2.6 * 105 J heat lost dQ = 2.6 * 105 J + (-8.0 * 105 J) dQ = - 5.4 * 105 J The negative is as a result of heat lost by the player