Câu 7: Một mạch điện xoay chiều có nguồn điện áp u(t) = 200 sin100 t, phụ tải gồm 3 điện trở R1 = 20 , R2 = 45 , R3 = 35 ghép nối tiếp nhau. Tính điện áp hiệu dụng trên từng điện trở? A. U1 = 90V, U2 = 40V, U3 = 70V
B. U1 = 45V, U2 = 20V, U3 = 35V
C. U1 = 40V, U2 = 90V, U3 = 70V
D. U1 = 30V, U2 = 50V, U3 = 20V

An uplifted block of rock between two normal faults

Consider an ordinary, helium-filled party balloon with a volume of 2.2 ft3. the lifting force on the balloon due to the outside air is the net resultant of the pressure distribution exerted on the exterior surface of the balloon. using this fact, we can derive archimedes’ principle, namely that the upward force on the balloon is equal to the weight of the air displaced by the balloon. assuming that the balloon is at sea level, where the air density is 0.002377 slug/ft3, calculate the maximum weight that can be lifted by the balloon. note: the molecular weight of air is 28.8 and that of helium is 4.

Charge is distributed along the entire x-axis with uniform density λ. how much work does the electric field of this charge distribution do on an electron that moves along the y-axis from y = a to y = b? (use the following as necessary: a, b, ε0, λ, and q for the charge on an electron.)