A 85.0-gram lead bullet hits a steel plate, both initially at 20 °C. The bullet melts and splatters on impact. Assuming that the bullet receives 88% of its kinetic energy as heat energy, at what minimum speed must it be traveling to melt on impact? (The melting temperature of Lead is 327°C)

Because water is a much more efficient thermal conductor than air, marine mammals often have thick layers of blubber (under-skin fat, with a thermal conductivity of 0.250 W/(m °C)) and a small surface-to-volume ratio to minimize the loss of energy by heat to the surrounding water. The beluga whale, Delphinapterus leucas, is a species of whale native to the Arctic and sub-Arctic regions. The core body temperature of this whale is usually 37.0°C, and its basal metabolic rate (BMR) is 7.30 x 104 kJ/day. The beluga often finds itself near the Arctic ice sheet, where the water temperature is very close to 0°C. (a) Modeling the body of the whale as a cylinder of length h = 4.10 m and diameter d = 1.20 m,estimate the average thickness (in cm) of the beluga's blubber required to keep the core temperature of the whale fixed at 37.0°C. (For simplicity, treat the blubber layer on the lateral cylindrical surface as a rectangular slab with a constant area. Take the front and rear surfaces of the…

The walls of a furnace are made of 1.2-ft-thick concrete (k = 0.64 Btu/h·ft·°F and a = 0.023 ft2/h). Initially, the furnace and the surrounding air are in thermal equilibrium at 70°F. The furnace is then fired, and the inner surfaces of the furnace are subjected to hot gases at 1800°F with a very large heat transfer coefficient. Determine how long it will take for the temperature of the outer surface of the furnace walls to rise to 70.1°F.

An insulated Thermos contains 140 cm³ of hot coffee at 92.0°C. You put in a 18.0 g ice cube at its melting point to cool the coffee. By how many degrees has your coffee cooled once the ice has melted and equilibrium is reached? Treat the coffee as though it were pure water and neglect energy exchanges with the environment. The specific heat of water is 4186 J/kg-K. The latent heat of fusion is 333 kJ/kg. The density of water is 1.00 g/cm³. Number i Units

A heavy pot made of copper has a mass of 2.24 kg (including the lid) and is heated in an oven to a temperature of 154 °C. You pour 0.12 kg of water at 26.0 °C into the pot and quickly close the lid so that no steam can escape. We assume that no heat is lost to the surrounding. For copper, Ccopper 390 J/(kg.K) For water, Cwater 4190 J/(kg.K), L, = 2256 kJ/kg, L; = 333 kJ/kg. %3D What is the final mass of steam in the pot? on

Week 4 #18 A copper bar of thermal conductivity 401 W/(m·K) has one end at 114°C and the other end at 24.0°C. The length of the bar is 0.110 m, and the cross-sectional area is 1.00 × 10−6 m2. If two such bars were placed in series (end to end) between the same constant-temperature baths, what would the rate of heat conduction  ? be? ______W

A copper block with a mass of 400 grams is cooled to 77 K by being immersed in liquid nitrogen. The block is then placed in a Styrofoam cup containing some water that is initially at +50.0°C. Assume no heat is transferred to the cup or the surroundings. The specific heat of liquid water is 4186 J/(kg °C), of solid water is 2060 J/(kg °C), and of copper is 385 J/(kg °C). The latent heat of fusion of water is 3.35 x 105 J/kg. What is the mass of water in the cup, if the final temperature is -25.0°C?

A dog loses a lot of heat by panting. The air rushing over the upper respiratory tract causes evaporation and thus heat loss. A dog typically pants pants at a rate of around 304 pants per minute. As a rough calculation, assume that one pant causes 0.0400 g of water to be evaporated from the respiratory tract. What is the rate of heat loss for the dog by panting? The heat of vaporization for water is 2256 kJ/kg.