đặt lần lượt các điện tích q1 = 1nC, q2 = -1nC, q3 = 1nC, q4 = 1nC vào các đỉnh A, B, C, D của chữ nhật, kích thước 20cm x 40cm trong không khí. Tính điện thế tại O là điểm giao của 2 đường chéo hình chữ nhật, chọn góc điện thế tại vô cùng.

A0.750 kg aluminum pan is removed from the stove and plunged into a sink filled with 10.0 kg of water at 293 k. the water temperature quickly rises to 297 k. what was the initial temperature of the aluminum pan? the specific heat of aluminum is ca = 900 j/(kgk) and water is cw = 4190 j/(kgk)

In which type of system is power held solely by the central government and not shared with regional governments? group of answer choices federal unitary confederate oligarchic

Two kilograms of air within a piston–cylinder assembly executes a carnot power cycle with maximum and minimum temperatures of 800 k and 300 k, respectively. the heat transfer to the air during the isothermal expansion is 60 kj. at the end of the isothermal expansion the volume is 0.4 m3. assume the ideal gas model for the air. determine the thermal efficiency, the volume at the beginning of the isothermal expansion, in m3, and the work during the adiabatic expansion, in kj.