JROTC - Mechanical Comprehension - Quiz, Flashcards & Trivia

1. Which term below describes the opposite of an increase in speed?

Velocity

Deceleration

Acceleration

Rotation

Deceleration means slowing down.

Explanation

Deceleration means slowing down.

2. Which principle of mechanical motion is used in the design of a roller coaster?

Momentum

Friction

Acceleration

All of the above

Acceleration must be considered in designing the maximum rise of the first hill. Momentum must be considered to ensure the train gets back to the starting point, since it has no motor. Friction must be considered in the design of the braking system.

Explanation

Acceleration must be considered in designing the maximum rise of the first hill. Momentum must be considered to ensure the train gets back to the starting point, since it has no motor. Friction must be considered in the design of the braking system.

3. What is a hoist used for?

Lift objects

Cut metals

Cut wood

Crunch metal

4. A valve is used to perform which of the following functions?

Increase the temperature of a gas

Aid evaporation of a liquid

Control the flow of a liquid

Decrease the density of a gas

Valves are placed in piping systems and can be opened or closed in order to control the flow of liquids or gasses.

Explanation

Valves are placed in piping systems and can be opened or closed in order to control the flow of liquids or gasses.

5. Which mechanical components are typically used between a wheel and an axle to reduce friction?

Springs

Bearings

Hinges

Levers

A set of bearings is typically a set of small metal balls packed in a groove and lubricated with grease or oil. The wheel rubs against one side of each ball, and the axle rubs against the other side. The net effect is that the wheel rolls much more easily.

Explanation

A set of bearings is typically a set of small metal balls packed in a groove and lubricated with grease or oil. The wheel rubs against one side of each ball, and the axle rubs against the other side. The net effect is that the wheel rolls much more easily.

6. A wrench is used to turn a bolt that has 20 threads per inch. After 15 complete turns of the wrench, the bolt will have moved:

1/8 inch

1/4 inch

3/4 inch

2/3 inch

7. A block of steel has a density of 0.29 pounds per cubic inch. If the block has dimensions of 1 inch by 1 inch by 3 inches, what is the weight?

0.29 pounds

0.36 pounds

0.87 pounds

0.99 pounds

The volume of the block can be calculated by multiplying its length by its width by its height, or 1 times 1 times 3, which equals 2 cubic inches. The weight is the density multiplied by its volume, which is 3 cubic inches multiplied by 0.29 pounds per cubic inch, which equals 0.87 pounds.

Explanation

The volume of the block can be calculated by multiplying its length by its width by its height, or 1 times 1 times 3, which equals 2 cubic inches. The weight is the density multiplied by its volume, which is 3 cubic inches multiplied by 0.29 pounds per cubic inch, which equals 0.87 pounds.

8. To lift a 600 pound piano, Tom and Jerry decide to use a plank placed under one end of the piano. The plank is 3 feet long. If a fulcrum is placed under the plank, one foot away from the piano, how much force must be applied to the plank to lift the piano?

100 pounds

125 pounds

140 pounds

150 pounds

9. Which action describes a clock pendulum swaying back and forth?

Gravity

Periodic motion

Acceleration

Velocity

10. What will a bar of steel do if it is heated at high temperatures?

Contract

Expand

Bend

Harden

11. Water is flowing into a tank at the rate of 180 gallons per minute. However, the tank has a leak, and water is leaking out at the rate of 2 gallons per second. How long will it take to add 120 gallons?

1 minute

2 minutes

3 minutes

4 minutes

12. If a train moves at 70 MPH and travels for 90 minutes, how many miles does it travel?

105 miles

109 miles

630 miles

13. A wrench uses which simple machine to turn a bolt?

Pulley

Hoist

Wheel and axle

Lever

14. Water is flowing into a tank through pipe A at 6 gallons per minute and through pipe B at 7 gallons per minute. The water is flowing out of the tank through pipe C at 8 gallons per minute. How much more water will be in the tank at the end of 5 minutes.

15 gallons

25 gallons

32 gallons

50 gallons

15. A garden hose is used to siphon the water out of an above-ground swimming pool. What makes the water flow out of the pool and through the garden hose?

Weight of the water

Water pressure

Air pressure

Air and water pressure in combination

JROTC - Mechanical Comprehension

1. Which term below describes the opposite of an increase in speed?

2.

What first name or nickname would you like us to use?

2. Which principle of mechanical motion is used in the design of a roller coaster?

3. What is a hoist used for?

4. A valve is used to perform which of the following functions?

5. Which mechanical components are typically used between a wheel and an axle to reduce friction?

6. A wrench is used to turn a bolt that has 20 threads per inch. After 15 complete turns of the wrench, the bolt will have moved:

7. A block of steel has a density of 0.29 pounds per cubic inch. If the block has dimensions of 1 inch by 1 inch by 3 inches, what is the weight?

8. To lift a 600 pound piano, Tom and Jerry decide to use a plank placed under one end of the piano. The plank is 3 feet long. If a fulcrum is placed under the plank, one foot away from the piano, how much force must be applied to the plank to lift the piano?

9. Which action describes a clock pendulum swaying back and forth?

10. What will a bar of steel do if it is heated at high temperatures?

11. Water is flowing into a tank at the rate of 180 gallons per minute. However, the tank has a leak, and water is leaking out at the rate of 2 gallons per second. How long will it take to add 120 gallons?

12. If a train moves at 70 MPH and travels for 90 minutes, how many miles does it travel?

13. A wrench uses which simple machine to turn a bolt?

14. Water is flowing into a tank through pipe A at 6 gallons per minute and through pipe B at 7 gallons per minute. The water is flowing out of the tank through pipe C at 8 gallons per minute. How much more water will be in the tank at the end of 5 minutes.

15. A garden hose is used to siphon the water out of an above-ground swimming pool. What makes the water flow out of the pool and through the garden hose?