HRS - Ask. Learn. Share Knowledge. Logo

Questions in engineering

[Done] Use the Laplace transform to solve the given initial-value problem. [tex]2 y^{\prime \prime}+3 y^{\prime \prime}-3 y^{\prime}-2 y=e^{-t}, \quad y(0)=0, \quad y^{\prime}(0)=0, \quad y^{\prime \prime}(0)=1[/tex] [tex]y(t)=[/tex]

[Done] When metering in zeotropes, the refrigerant must be ______ before entering the compressor. A. evaporated B. a liquid C. a charging device D. a vapor

[Done] Which of the following most closely affects pressure? a) Diameter b) Oil return c) Flow direction d) Length e) Installation

[Done] WATER FLOWS FROM A TANK OF CONSTANT CROSS-SECTIONAL AREA 50 [tex]FT ^2[/tex] THROUGH AN ORIFICE OF CONSTANT CROSS-SECTIONAL AREA [tex]\frac{ 1 }{ 4 }[/tex] [tex]FT ^2[/tex] LOCATED AT THE BOTTOM OF THE TANK. INITIALLY, THE HEIGHT OF THE WATER IN THE TANK WAS 20 FT, AND [tex]T[/tex] SEC LATER IT WAS GIVEN BY THE EQUATION [tex]2 \sqrt{h}+\frac{1}{25} t-2 \sqrt{20}=0 \quad 0 \leq t \leq 50 \sqrt{20}[/tex] HOW FAST WAS THE HEIGHT OF THE WATER DECREASING WHEN ITS HEIGHT WAS 3 FT? A. [tex]100 \sqrt{5}+50 \sqrt{3}[/tex] FT/SEC B. [tex]\frac{\sqrt{3}}{25}[/tex] FT/SEC C. [tex]100 \sqrt{5}-50 \sqrt{3} FT / SEC[/tex] D. [tex]\frac{3}{25}[/tex] FT/SEC

[Done] Match the refrigeration system problem with the solution. Trapped air in a system Dirty piping Pinhole leak in hoses 1. Replace the hose. 2. Ensure that system valves are open before starting an evacuation. 3. Sweep the system with dry nitrogen before evacuation.

[Done] Refer to the law of laminar flow. Consider a blood vessel with radius 0.01 cm, length 3 cm, pressure difference 3,500 dynes/cm² and viscosity = 0.028. Find the velocity of the blood at radius r= 0.002. Round your answer to the nearest whole number. The velocity of the blood is ___ cm/s.

[Done] The best way to keep refrigerant velocity up is to a) use a stronger compressor. b) use more lubrication. c) make the lines larger. d) make the lines smaller.

[Done] In DC Theory, what does the Left-Hand Rule for generators show? A. The amount of resistance in conductors B. The motion, direction of magnetic field, and the direction of the current flow for electromagnetic induction C. The motion, direction of magnetic field, and direction of current flow for 3-pole switches D. The power, wattage, and voltage produced by a circuit

[Done] A metal fabricator checked the placement of a 2 7/8 inch diameter hole relative to the edge of the part she was building. Calculate the edge-to-centre distance for the hole. State your answer as a mixed number in lowest terms.

[Done] A farmer named Mr. Sijamba has a large dog which is part wolf, a goat, and several heads of cabbage. In addition, the farmer owns a north barn and a south barn. The farmer, dog, cabbages, and goat are all in the south barn. The farmer has chores to perform in both barns. However, if the dog is left with the goat when the farmer is absent, he will bite the goat, and if the goat is left with the cabbages, it will eat them. To avoid disaster, Mr. Sijamba asks you to build a small portable computer system having four switches, representing the farmer, dog, goat, and cabbages. If a switch is connected to a battery (V1), the character represented by the switch is in the south barn; if the switch is connected to ground (V2), the character is in the north barn. The output of the computer system goes to a lamp, which is to light whenever there is an impending disaster. Thus the farmer can go about his chores, using the computer system to tell him what he must take with him from one barn to another in order to avoid trouble. TASK: in groups of 4: (a) Design the computer system and build it using logic gates. (b) Write a Truth Table for all the possibilities. Indicate a disaster by the symbol L = 1. Transfer the Truth Table data onto a Karnaugh Map and simplify the L-Function. (c) Implement the simplified L-Function using basic logic gates.