EEI Tech Mechanical Concept Flashcards

When should pressurized air be introduced into the cylinder to lower the piston?

Answer: Point A

To lower the piston, pressurized air must be introduced into the cylinder above the piston, pushing it downwards. Point A is located at the top of the cylinder, directly above the piston. Introducing air at Point B would push the piston upwards.

Which switch should be turned off to turn on the light?

Answer: Switch C

The light bulb is connected in parallel with Switch C. When Switch C is closed (on), it creates a short circuit, diverting current away from the light bulb and preventing it from lighting up. To turn the light on, current must flow through the bulb, so Switch C must be open (off) to force the current through the bulb. Switches A and B must be closed (on) for the circuit to be complete.

Which of the two tanks will cool water that has been boiled to the same temperature faster?

Answer: Tank A

Tank A, being wider and shallower, has a larger surface area exposed to the air compared to Tank B. A larger surface area facilitates a faster rate of heat transfer through evaporation and convection. This increased heat dissipation allows the water in Tank A to cool down more quickly.

Which pole does the weight exert the greatest pressure on?

Answer: Pole 1

The pole closer to the applied weight will bear a greater share of the load, resulting in higher pressure. This is due to the principle of levers and torque; the pole closer to the force has a shorter lever arm and thus supports more of the weight to maintain equilibrium. If the weight is not centered, the support closer to it will experience a disproportionately larger force.

Which would hit the ground first if a car and a bowling ball were both thrown off a 100-foot cliff at the same time?

Answer: There is no difference.

According to Galileo's law of falling bodies, in the absence of air resistance, all objects fall at the same rate regardless of their mass. Both a car and a bowling ball experience the same acceleration due to gravity (approximately 9.8 m/s²), meaning they would hit the ground simultaneously. While air resistance exists, for these objects, its effect is generally not significant enough to cause one to hit substantially earlier than the other in this scenario.