Engineering Answers

•Derive the transfer function G1(s) = X(s)/U(s) for the first-order system given by the dynamic equation: dx/dt + kx = u(t).

•Obtain and sketch the impulse response for the given first-order system, when

(i) k >0

(ii) k=0

(iii) k<0

Calculate the capacity of a fuel tank and the fuel pump capacity of a Diesel power plant with

5500 kw installed capacity and 50% plant capacity factor. You have to procure fuel monthly with

150% contingency.

A Dodecane fuel will be used in an IC Engine. The Air-Fuel ratio is 30:1. Calculate the percent

excess air.

5. Two shafts 30 in. apart, each carrying a four-step pulley, are to be connected by a cross belt. The driving shaft is to turn 180 rpm while the driven shaft is to turn 50, 150, 250, and 600 rpm. The smallest step of the driver is 10 in. in diameter. Find (a) the diameters of all the steps, (b) angle of contact for each pair of pulleys, and (c) belt length.

4. A pulley 600 mm. in diameter transmits 40 kW at 500 rpm. The arc of contact between the belt and pulley is 144° having a center distance of 1100 mm. Determine: (a) diameter of the driven pulley for open belt drive, (b) speed of the driven pulley, and (c) belt length for open belt connection.

Now, what if, instead, you sold the house for less than you paid for it—say, for $187,500? The same equation can be used to calculate your loss, or the negative rate of return, on the transaction.

Say that you buy a house for $250,000 (for simplicity let's assume you pay 100% cash). Six years later, you decide to sell the house maybe your family is growing and you need to move into a larger place. You are able to sell the house for $335,000, after deducting any realtor's fees and taxes. Find simple rate of return on the purchase and sale of the house.

Brigham Tea, Inc., is a processor of low acid tea. The company is contemplating purchasing equipment for an additional processing line. The additional processing line would increase revenues by $90,000 per year. Incremental cash operating expense would be $40,000 per year. The equipment would cost $180,000 and have a nine-year life. No salvage value is projected.