Consider the analog signal: Xa(t) = 3cos(300t). Determine the minimum sampling avoid aliasing. If this signal is sampled at 300 Hz, what is the frequency of the signal reconstructed from the sampled data points? If this signal is sampled at 200 Hz, what is the frequency of the signal reconstructed from the sampled data points?

Apipe with an outside diameter of 15 cm is exposed to an ambient air and surrounding temperature of -20°c. the pipe has an outer surface temperature of 65°c and an emissivity of 0.85. if the rate of heat loss from the pipe surface is 0.95 kw per meter of length, the external convective heat transfer coefficient (h) is: (a) 12.5 w/m"k (b) 18.6 w/mk (c) 23.7 w/mk (d) 27.9 w/mk (e) 33.5 w/mk

The higher the astm grain size number, the finer the gran is. a)-true b)-false

Hydraulic fluid with a sg. of 0.78 is flowing through a 1.5 in. i.d. pipe at 58 gal/min. the fluid has an absolute viscosity of 11.8 x 105 lbf-sec/ft2. is the flow laminar, turbulent or within the critical range? give both a numerical reynolds number and a term answer.