工程與科技 大學 約4年以前

求高手幫忙

1(35%) Determine the Fourier series representation of the periodic signal x(t) shown in Fig. 1. Plot its frequency spectrum Ck/ versus frequency 0, 020, where Ck is the Fourier series coefficient. xt (0) 20 -6 -4 -2 0 2 士 4 16 10 十-20 Fig. 1

工程與科技 大學 約4年以前

化工-單元操作 大神求解

13. Furnace stack-E. Air (pe = 0.08 lbm/ft3) flows through a furnace where it is burned with fuel to produce a hot gas (Pg 0.05 lbm/ft3) that flows up the stack, as in Fig. P1.13. The pressures in the gas and the immediately surrounding air at the top of the stack at point A are equal. A Gas out A Air Air H= 100 ft Gas Air in Furnace B Ah Water manometer (relative positions of levels not necessarily correct) Fig. P1.13 Furnace stack. What is the difference Ah (in.) in levels of the water in the manometer con- nected between the base B of the stack and the outside air at point C? Which side rises? Except for the pressure drop across the furnace (which you need not