A box with sides of length 40 cm is made up of six pieces of concrete of thickness 5 mm. The inside of the box is filled with 10
0 moles of a diatomic ideal gas while the temperature outside the box is 30°C. At what rate is the temperature of the gas increasing when the gas is at -40°C? (The thermal conductivity of concrete is 0.33 W/(m×K).)a) 1.22 °C/s b) 1.45 °C/s c) 1.68 °C/s d) 2.13 °C/s e) 2.90 °C/s
The combined magnetic force of the magnetized wire coil and iron bar makes an electromagnet very strong. In fact, electromagnets are the strongest magnets made. An electromagnet is stronger if there are more turns in the coil of wire or there is more current flowing through it.
