Chiếu chùm sáng song song có bước sóng 576 nm thẳng góc tới một khe hẹp có bề rộng b = 0,1 mm. Ngay sau khe hẹp đặt một thấu kính hội tụ có tiêu cự f = 1 m, màn đặt trên mặt phẳng tiêu của thấu kính. Xác định bề rộng của vân sáng trung tâm (tính ra milimet - mm).

The earth is constantly spinning on its axis, like you might spin a basketball on your finger. it is this spinning of the earth that causes

Asteel tube (k=50 w/mk) of inner and outer diameter di = 20mm and do=26mm, respectively, is used to transfer heat from hot gases flowing over the tube (h-hot = 200w/m2k) to cold water flowing through the tube (h-cold = 8000 w/m2k). what is the cold-side overall heat transfer coefficient uc? to enhance heat transfer 16 straight fins of rectangular profile are installed longitudinally along the outer surface of the tube. the fins are equally spaced around the circumference of the tube, each having a thickness of 2mm and a length of 15mm. what is the corresponding overall heat transfer coefficient uc? *solve for uc in both cases*

8. what is the orbital gravitational force of jupiter? how much stronger is this force than venus?