OAR OAR Mechanical Reasoning 4

Question 1

A boat floats because the buoyant force equals its weight. If cargo is added until the boat sinks lower in the water, the buoyant force:

Accepted Answer

Increases as more water is displaced

Answer

Decreases as the boat sinks lower

Answer

Remains the same regardless of depth

Answer

Becomes zero below the waterline

Question 2

A screw with 20 threads per inch is turned 5 full rotations. How far does it advance into the material?

Accepted Answer

1/4 inch

Answer

4 inches

Answer

20 inches

Answer

100 inches

Question 3

A refrigerator removes heat from inside by using a refrigerant. The compressor's role in this cycle is to:

Accepted Answer

Pressurize the refrigerant so it can release heat outside

Answer

Cool the refrigerant by expanding it rapidly

Answer

Absorb heat directly from the food compartment

Answer

Convert electrical energy into cold air

Question 4

A 60 kg person stands on a scale in an elevator accelerating upward at 2 m/s². What does the scale read? (g = 10 m/s²)

Accepted Answer

720 N

Answer

480 N

Answer

600 N

Answer

840 N

Question 5

Three resistors of 6 Ω each are connected in parallel. What is the total resistance of the circuit?

Accepted Answer

2 Ω

Answer

0.5 Ω

Answer

6 Ω

Answer

18 Ω

Question 6

A wheel and axle system has a wheel radius of 30 cm and an axle radius of 5 cm. What mechanical advantage does it provide?

Accepted Answer

6

Answer

1/6

Answer

1

Answer

150

Question 7

When a gas in a sealed container is heated at constant volume, its pressure:

Accepted Answer

Increases proportionally

Answer

Decreases proportionally

Answer

Stays the same

Answer

First increases then decreases