Science

A lift with its occupants has a mass of 5000 kg . Calculate the tension in the elevator cable if it is: a) accelerated upward by 1.5 m/s 2 ; b) decelerated upward by 1.5 m/s2; c) accelerated downward by 1.5 m/s 2 ; d) decelerated downward by 1.5 m/s 2 . The spring of a cork gun has a spring constant of 20 N/m . A cork is shot horizontally from 10 m above the ground using this gun. How far the cork will travel before it hits the ground; ignore the air resistance in the calculation.

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4. (20 pts.) Below is a liquid-solid phase diagram for a mixture of two components, A and B. 300 750 p=1 700 liquid 650 600 $ 2550 500 450 400 40 350 300 0 01 02 03 04 05 06 07 08 09 1 . (a) For the points labeled through 4 along the vertical line at z = 0.2, provide the number of phases present, a description of each phase, and the mole fraction of B in each phase. (To receive full credit, your descriptions must be clear and unambiguous.) 1 (b) What is the melting temperature of pure A? (C) What is the melting temperature of pure B? (d) What is the eutectic temperature? (e) What is the eutectic composition? (1) What is the freezing point of a liquid with z=0.2?

EXPERT ANSWER Ans) A) at point 1) – mixture at melting point At point 2)- A is solid and liquid At point 3)- mixture is at freezing point At poin 4)- mixture is solid Mole fraction of B at (z=0.2) = 0.2 B) – from graph we can see Melting point of pure A = …

4. (20 pts.) Below is a liquid-solid phase diagram for a mixture of two components, A and B. 300 750 p=1 700 liquid 650 600 $ 2550 500 450 400 40 350 300 0 01 02 03 04 05 06 07 08 09 1 . (a) For the points labeled through 4 along the vertical line at z = 0.2, provide the number of phases present, a description of each phase, and the mole fraction of B in each phase. (To receive full credit, your descriptions must be clear and unambiguous.) 1 (b) What is the melting temperature of pure A? (C) What is the melting temperature of pure B? (d) What is the eutectic temperature? (e) What is the eutectic composition? (1) What is the freezing point of a liquid with z=0.2? Read More »

4. (20 pts.) Below is a liquid-solid phase diagram for a mixture of two components, A and B. 700 T(K) 800 750 p liquid 650 600 550 500 450 400 40 350 300 0 01 02 03 04 05 06 07 08 09 1 24 (a) For the points labeled 1 through 4 along the vertical line at 20.2, provide the number of phases pret a description of each phase, and the mole fraction of B in each phase. (To receive full credit, descriptions must be clear and unambiguous.) I (b) What is the melting temperature of pure A? © What is the melting temperature of pure B? (d) What is the eutectic temperature? (e) What is the eutectic composition? ( What is the freezing point of a liquid with 2-0.27 (C) For the two-component system described by the phase diagram in problem #4, sketch cooling curves for solutions with Zp = 0,25 = 0.2, and zp = 0.4. The cooling curves should start at 800 K. What quantity does the horizontal axis correspond to?

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The Environmental Protection Agency (EPA) wants to restrict the amount of pollutants added by a company to the river water. The concentrations of phenol and nitrogen in the water are to be restricted to, respectively, P and N lbs. MG (million gallons) on a daily basis. The river has a flow of M MG/day. The company diverts a portion of the river water, adds the pollutants, namely, phenol and nitrogen, to it, and sends the water back to the river. The company has four possible ways to treat the water it uses before returning it to the river. The characteristics of each treatment are given in the following table:

The Environmental Protection Agency (EPA) wants to restrict the amount of pollutants added by a company to the river water. The concentrations of phenol and nitrogen in the water are to be restricted to, respectively, P and N lbs. MG (million gallons) on a daily basis. The river has a flow of M MG/day. The …

The Environmental Protection Agency (EPA) wants to restrict the amount of pollutants added by a company to the river water. The concentrations of phenol and nitrogen in the water are to be restricted to, respectively, P and N lbs. MG (million gallons) on a daily basis. The river has a flow of M MG/day. The company diverts a portion of the river water, adds the pollutants, namely, phenol and nitrogen, to it, and sends the water back to the river. The company has four possible ways to treat the water it uses before returning it to the river. The characteristics of each treatment are given in the following table: Read More »