Basic Physics

Question 1

If a double-acting actuating cylinder in a 3,000 psi system has a piston with a surface area of three square inches on the extension side, and a rod with a cross-section area of one square inch attached to the piston on the other side, approximately how much force will the actuator be able to produce when retracting?

Answer 1

6,000 pounds.

Question 2

The boiling point of a given liquid varies…

Answer 2

directly with pressure.

Question 3

Which of the following is NOT considered a method of heat transfer?

Answer 3

Diffusion.

Question 4

An engine that weighs 350 pounds is removed from an aircraft by means of a mobile hoist. The engine is raised 3 feet above its attachment mount, and the entire assembly is then moved forward 12 feet. A constant force of 70 pounds is required to move the loaded hoist. What is the total work input required to move the hoist?

Answer 4

840 foot-pounds.

Question 5

Which condition is the actual amount of water vapor in a mixture of air and water?

Answer 5

Absolute humidity.

Question 6

Under which conditions will the rate of flow of a liquid through a metering orifice (or jet) be the greatest (all other factors being equal)?

Answer 6

Unmetered pressure, 17 PSI; metered pressure, 5 psi; atmospheric pressure, 14.7 psi.

Question 7

The amount of force applied to rope A to lift the weight is…

Answer 7

15 pounds.

Question 8

Which will weigh the least?

Answer 8

35 parts of dry air and 65 parts of water vapor.

Question 9

Which is the ratio of the water vapor actually present in the atmosphere to the amount that would be present if the air were saturated at the prevailing temperature and pressure?

Answer 9

Relative humidity.

Question 10

The speed of sound in the atmosphere…

Answer 10

changes with a change in temperature.

Question 11

The speed of sound in the atmosphere is most affected by variations in which of the following?

Answer 11

Ambient temperature.

Question 12

If the volume of a confined gas is doubled (without the addition of more gas), the pressure will (assume the temperature remains constant)….

Answer 12

be reduced to one-half its original value.

Question 13

If the temperature of a confined liquid is held constant and its pressure tripled, the volume will…

Answer 13

remain the same.

Question 14

How much work input is required to lower (not drop) a 120-pound weight from the top of a 3-foot table to the floor?

Answer 14

360 foot-pounds.

Question 15

Which atmospheric conditions will cause the true landing speed of an aircraft to be the greatest?

Answer 15

High temperature with high humidity.

Question 16

If the fluid pressure is 800 PSI in a 1/2-inch line supplying an actuating cylinder with a piston area of 10 square inches, the force exerted on the piston will be…

Answer 16

8,000 pounds.

Question 17

In physics, which of the following factors are necessary to determine power?

Answer 17

Force exerted, distance moved, and time required.

Question 18

Answer 18

40 pounds.

Question 19

Which statement concerning heat and/or temperature is true?

Answer 19

Temperature is a measure of the kinetic energy of the molecules of any substance.

Question 20

What is absolute humidity?

Answer 20

The actual amount of water vapor in a mixture of air and water.

Question 21

The temperature to which humid air must be cooled at constant pressure to become saturated is called…

Answer 21

dewpoint.

Question 22

If both the volume and the absolute temperature of a confined gas are doubled, the pressure will…

Answer 22

not change.

Question 23

If all, or a significant part of a stall strip is missing on an airplane wing, a likely result will be…

Answer 23

asymmetrical lateral control at or near stall angles of attack.

Question 24

The purpose of stall strips on airplane wings is to…

Answer 24

ensure that the wing root areas stall first.

Question 25

An airplane wing is designed to produce lift resulting from…

Answer 25

positive air pressure below the wing’s surface and negative air pressure above the wing’s surface along with the downward deflection of air.

Question 26

Which of the following is Newton’s first law of motion, generally termed the law of inertia?

Answer 26

Objects at rest tend to remain at rest and objects in motion tend to remain in motion at the same speed and in the same direction, unless acted on by an external force.

Question 27

The purpose of aircraft wing dihedral is to…

Answer 27

increase lateral stability.

Question 28

Aspect ratio of a wing is defined as the ratio of the…

Answer 28

wingspan of the mean chord.

Question 29

A wing with a very high aspect ratio (in comparison with a low aspect ratio wing) will have…

Answer 29

a low stall speed.

Question 30

The desired effect of using winglets on an aircraft’s wingtips is to…

Answer 30

increase the lift to drag ratio.

Question 31

The main rotor system on a helicopter is classified in three groups. Which of the listed is NOT one of these groups?

Answer 31

The flexible-beam rotor system.

Question 32

Which of the following statements is correct? (about helicopters)

Answer 32

When the collective pitch control lever is raised, the blade angle of all the rotor blades increases uniformly and they create the lift that allows the helicopter to take off vertically.