1. Use vector arrows to represent the velocity of a car that travels north at 50 mi/h and then travels east at 25 mi/h. 2. Another car travels northwest for 2 hours and covers a distance of 90 miles. What is the average velocity of the car?

A47.2 g block of copper whose temperature is 480 k is placed in an insulating box with a 91.8 g block of lead whose temperature is 200 k. (a) what is the equilibrium temperature of the two-block system? (b) what is the change in the internal energy of the two-block system between the initial state and the equilibrium state? (c) what is the change in the entropy of the two-block system? the heat capacities of copper and lead are 386 j/kg·k and 128 j/kg·k, respectively.