A spring-mass-damper system is fixed to its base. Assuming that x(t) denotes the position of the mass with respect to time, determine the equation of motion of the Rev A: Prof. Bryan W. Weber Page 2 of 5 Spring 2020 system. Sketch plots of the step response of the system when it is (a) underdamped, (b) critically damped, (c) overdamped.

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