An industrial outlet is discharging a 1.8 m/s waste stream with a BOD of 20 mg/L and a DO concentration of 1.5 mg/L into a river with a flow of 70 mº/s that contains 0.51 mg/L BOD and has an existing oxygen deficit of 1.2 mg/L If the saturated DO concentration is 9.50 mg/L, what is the initial deficit D. (mg/). In the Oxygen Sag Model for this situation? a. 1.37 mg/L
b. 1.0 mg/l
c. 1.2 mg/L
d. 8.0 mg/L

Coiled springs ought to be very strong and stiff. si3n4 is a strong, stiff material. would you select this material for a spring? explain.

What is a monomer? how do they form a ploymer from the view point of chemical bonding?

Afoot bridge is made as a simple deck, 4 m long, with a cross section 2 m (wide) and 20 cm thick, and made of wood. the deck is supported at the two ends. the maximum load allowable on the bridge is 10 tons, provided it is uniformly distributed on the deck. to sense this load, a strain gauge is placed at the center of the bridge and its resistance is monitored. if the sensor has a nominal resistance of 350 s2 and a gauge factor of 3.6, what is the reading of the strain gauge at maximum load? the modulus of elasticity for the wood used in the construction is 10 gpa.