Consider atmospheric air at u? = 2 m/s and t? = 300 k in parallel flow over an isothermal flat plate of length
l = 1 m and temperature ts = 350 k.

(a) compute the local convection coefficient at the leading and trailing edges of the hot plate with and without an unheated starting length of ? = 1 m.

(b) compute the average convection coefficient for the plate for the same conditions as part (a).

(c) plot the variation of the local convection coefficient over the plate with and without an unheated starting length.

On a average work day more than work place firs are reorted

An engine runs on the ideal diesel cycle. the cycle has a compression ratio of 20 and a cutoff ratio of 2. the highest temperature in the cycle is 1200 k. if the heat into the system is 300 kj/kg of working fluid and using variable specific heats determine the work produced per mass of working fluid

Tom is having a problem with his washing machine. he notices that the machine vibrates violently at a frequency of 1500 rpm due to an unknown rotating unbalance. the machine is mounted on 4 springs each having a stiffness of 10 kn/m. tom wishes to add an undamped vibration absorber attached by a spring under the machine the machine working frequency ranges between 800 rpm to 2000 rpm and its total mass while loaded is assumed to be 80 kg a) what should be the mass of the absorber added to the machine so that the natural frequency falls outside the working range? b) after a first trial of an absorber using a mass of 35 kg, the amplitude of the oscillation was found to be 10 cm. what is the value of the rotating unbalance? c) using me-3.5 kg.m, find the optimal absorber (by minimizing its mass). what would be the amplitude of the oscillation of the absorber?