1. A large copper tank is 3 m long when it’s at room temperature20 oC. When the tank is partially filled with hot water, itstemperature rises to 95 oC. What is the length of the copper tankat this temperature? The coefficient of linear expansion for copperis 17×10-6 /oC. (5pts)

2. When you press on the brake pedal of a car the car slowsdown. This means that the car’s kinetic energy decreases. You mightask where does that KE go? The answer is into heat and thereforethe brakes get hot. Let’s assume that the brake mechanism for thecar is made of steel and the total mass of the brakes is 20 kg.(Steel has a specific heat capacity of 460 J/(kg oC).)

(a) A car with mass 1,000 kg is moving at 20 m/s. What is thekinetic energy of the car? (5 pts)

(b) The car stops with its brakes, and the KE is transferred toheat in the brakes. By how much does the temperature rise insidethe brakes? (5pts)

3. Concrete has a coefficient of linear expansion of about 8 ×10-6/°C. If you were to build a bridge from concrete panels, youwould have to leave a gap between them so that the concrete panelswould have room to expand on a hot day. Suppose you leave a gap of1.5 cm between panels, and you require that the panels must expandby only 1.3 cm when the temperature rises by 60 °C. What is themaximum length of the concrete panels? (5 pts) 1

5. Here’s some data on thermal conductivity for variousmaterials (the units are W/(m°C): aluminum: k = 237 copper: k = 400iron: k = 72 If you had to select between kettles made of aluminum,copper and iron for boiling water on a stove top, which kettle typeshould you choose? (5 pts)

6. A 10 kg block of iron is dropped into a 10 kg pool of water.The temperature of the iron is initially 100 °C, and thetemperature of the water is initially 20 °C. Circle all thestatements that are true. (5 pts)

a. Heat moves from the iron into the water.

b. Heat moves from the water into the iron.

c. Heat moves so that the heat in the iron is equal to the heatin the water.

d. Heat moves so that the final temperature of the iron andwater are equal.

e. The final temperature of the water and iron will be greaterthan 20°C and less than 100 °C.