Nồng độ phần mol của một hỗn hợp khí trong buồng bảo quản CA cho táo ở 1oC và 105 Pa như sau: O2 : 2%; CO2 : 3%; và N2 : 95%. Tính: a) Nồng độ phần khối lượng của mỗi loại khí b) Khối lượng phân tử trung bình của hỗn hợp khí c) Khối lượng riêng của hỗn hợp khí d) Áp suất riêng phần của các khí thành phần.

Under conditions for which the same room temperature is maintained by a heating or cooling system, it is not uncommon for a person to feel chilled in the winter but comfortable in the summer. provide a plausible explanation for this situation (with supporting calculations) by considering a room whose air temperature is maintained at 20â°c throughout the year, while the walls of the room are nominally at 27â°c and 14â°c in the summer and winter, respectively. the exposed surface of a person in the room may be assumed to be at a temperature of 32â°c throughout the year and to have an emissivity of 0.90. the coefficient associated with heat transfer by natural convection between the person and the room air is approximately 2 w/m2 â‹…â‹… k. what is the ratio of the thermal resistance due to convection to the thermal resistance due to radiation in the summer? what is the ratio of thermal resistances in the winter

Which are examples of projectile motion? choose all that apply a. a soccer ball rolling across the ground in the northeast direction b. a car turning a corner, so it is heading south c. a javelin flying through the air d. a tennis ball lobbed over the net

The government has declared that a hurricane is likely to hit the east coast. which government division is part of acf and provides guidance to citizens? a. job opportunities for low-income individuals b. office of human services emergency preparedness and response c. assets for independence d. low-income home energy assistance program