PLTW-POE EOC

An engineer must design a control panel for a wind turbine, given the following guidelines:

o Two warning lamps (L1 & L2) turn on when the turbine speed exceeds 5000 rpm (S1)

o If the current through either lamp is stopped (lamp burns out) the other lamp must still be able to illuminate

o The total current must not exceed 0.50 A

Which design satisfies all of the engineer’s design criteria?

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Three students are designing a winch system. As part of the design process they find existing solutions, and identify why the solutions are not adequate or appropriate. Which step of the design process are the students completing?

• Research & define the problem

• Evaluate a Solution

• Develop a Solution

• Present Testing Results

A design team completed the above decision matrix to evaluate their ideas.

Which idea should the team pick as a solution based solely on the decision matrix? Idea #2, since it has the lowest cost

• Idea #2, since it has the lowest cost

• Idea #4, since it has the least complex idea

• Idea #3, since it has the highest decision matrix total

• Idea #6, since it ranks highest on the decision matrix summary

What type of simple machine is the shovel?

• 1st Class Lever

• 2nd Class Lever

• 3rd Class Lever

Which resource is a form of renewable energy?

• Biomass

• Coal

• Natural Gas

• Uranium

Which ammeter will display the highest current?

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A team of engineers has been assembled to design and create a renewable electrical energy generating and distribution system that utilizes wind, solar-electric, and fuel-cell energy conversion systems. The team just finished creating a decision matrix to compare the attributes of the various ideas. Which step from the design process is now occurring?

• Evaluate solution

• Generate Concepts

• Develop a solution

• Construct & test prototype

A 12 oz can of soda was left in a car on a hot day. In the morning, the soda temperature was 60°F with a gauge pressure of 40 psi. What will the gauge pressure be when the soda reaches 90°F (or 305 Kelvin)?

• 42.3 psi

• 43.2 psi

• 57.9 psi

• 60.0 psi

A pneumatic system consists of several identical 1.5 inch diameter cylinders to lift 450-pound pallets in a warehouse. The gauge pressure in the system reservoir remains at 75 psi, and the atmospheric pressure is 14.7 psi. Assuming that the weight of the pistons is negligible, determine the total number of 1.5-inch cylinders needed in the pneumatic system to lift the 450-pound load.

• 5

• 4

• 3

• 2

A bicycle pump is used to inflate a bicycle tire. When the pump is connected to the tire, the volume of the pump-tire system is 56 in3 and the gauge pressure is 65 lb/in2. The pump is given one stroke, and the volume of the pump-tire system is now 50 in3. Atmospheric pressure is 14.7 lb/in2 and the temperature of the pump and tire remains constant at 68?F.

What is the gauge pressure after the initial stroke of the bicycle pump?

• 72.80 lb/in.²

• 74.56 lb/in.²

• 87.50 lb/in.²

• 89.26 lb/in.²