Ion exchange is used to remove water hardness of a well water, which has a total hardness of 450 mg/L as CaCO3. The ion exchanger has leakage hardness of 15 mg/L as CaCO3. The percentage of water that is bypassed and blended is 30%. What is the final water hardness in the finished or treated water most nearly?

A. 105 mg/L as CaCO,
B. 110 mg/L as CaCO,
C. 125 mg/L as CaCO3
D. 150 mg/L as CaCO3

An electrical motor raises a 50kg load at a construct velencity .calculate the power of the motor, if it takes 40sec to raise the load through a height of 24m(take g =9.8n/g)

Calculate the bore of a cylinder that has a stroke of 18 inches and an extension time of 6 seconds at a flow rate of 4 gal/min.

Athin walled concentric tube exchanger is used to cool engine oil from 160°c to 60°c with water that is available at 25°c acting as a coolant. the oil and water flow rates are each at 2 kg/s, and the diameter of the inner tube is 0.5 m and the corresponding value of the overall heat transfer coefficient is 250 w/m2. oc. how long must the heat exchanger be to accomplish the desired cooling? cpwater=4.187 kj/kg-candcpengine el=2.035 kj/kg·°c, oil . 120]