Matter
Mass represents how much matter an object contains and doesn’t alter whether the object is on Earth, Venus, or in deep space. Why, then, does a scale show different weights for the same object in these places?
What is...
The force of gravity varies depending on the location
Energy is the capacity to do work, and potential energy is defined as stored energy or energy at rest. Based on typical classifications, identify the three main types of potential energy.
Energy due to an object’s position
Energy due to the distortion of an elastic body
Energy stored in chemical bonds that can produce work
Machines accomplish work by serving various purposes, such as transforming energy, transferring energy, multiplying force or speed, or changing the direction of a force. A system of gears in a car increases the rotational speed of the wheels compared to the engine’s output. What purpose does this example best represent?
Multiplying speed through applied force
Newton’s First Law of Motion describes how objects behave with respect to motion and external forces. What is the correct definition of this law?
Objects at rest tend to stay at rest, and objects in motion tend to stay in motion at the same speed and direction, unless acted upon by an external force.
The kinetic theory of gases provides a framework for understanding gas behavior, leading to laws like Boyle’s Law (V₁P₁ = V₂P₂). When the temperature of a gas sample is held constant, if the volume is doubled, what happens to the absolute pressure?
Is reduced to half the former value.
On Earth, the acceleration due to gravity is 32.2 feet per second per second (fps/s). A mass of 1 slug weighs 32.2 pounds (lb) under these conditions because weight is the force of gravity acting on mass (Weight = Mass × Gravity). If a force of 1 pound is applied to a 1-slug mass, it accelerates at 1 foot per second squared (ft/s²). What does this tell us about the relationship between mass, weight, and gravity?
A 1-slug mass weighs 32.2 pounds on Earth due to Earth’s gravitational force
Kinetic energy is the energy of motion, defined by the formula Kinetic Energy = ½ × Mass × Velocity². Given this relationship, which of the following changes would most likely result in the greatest increase in kinetic energy of an object?
Doubling the velocity
The six simple machines—lever, pulley, wheel and axle, inclined plane, screw, and gear—are based on just two fundamental principles according to physicists: the lever and the inclined plane. A block and tackle system is used to lift a heavy crate with less effort. What basic principle does this machine rely on?
Lever
Newton’s Third Law of Motion explains how forces interact between objects. What is the correct definition of this law?
If a force is applied to an object, the object will supply a resistive force exactly equal to and in the opposite direction of the force applied.
Charles’ Law (V₁T₂ = V₂T₁) describes gas behavior under constant pressure, derived from the kinetic theory of gases. If the pressure of a gas sample is held constant and the temperature decreases, what happens to the volume?
Also decreases.
Specific gravity is a measure used to compare the density of a liquid to that of water. When we determine the specific gravity of a liquid, what are we actually comparing?
The weight of the liquid to the weight of an equal volume of water
Work is defined as a force overcoming a resistance through a measurable distance, calculated as Work = Force × Distance. In the English system, work is measured in foot-pounds (ft-lb). Suppose a tow tractor applies a force of 6,000 lb to move a 140,000-lb airplane horizontally 50 ft into a hangar. How much work is accomplished, and what does this indicate about the force required compared to lifting the airplane vertically?
300,000 ft-lb; the force is much less than the airplane’s weight
A simple machine can accomplish work by multiplying either force or speed, but not both simultaneously—gaining one requires losing the other. What term describes the gain provided by a machine in this context?
Mechanical advantage
Newton’s Second Law of Motion describes how force affects an object’s motion. What is the correct definition of this law?
When a force acts upon a body, the momentum of that body is changed. The rate of change of momentum is proportional to the applied force.
The General (or Ideal) Gas Law describes the behavior of gases under varying conditions of pressure, volume, and temperature. How does it relate to Boyle’s Law and Charles’ Law?
Combines Boyle’s Law and Charles’ Law
A hydrometer is a device used to measure the specific gravity of liquids. It consists of a weighted glass float inside a larger tube, where the liquid is drawn in using a suction bulb. The float’s graduated scale is read at the liquid’s surface. When immersed in pure water, the hydrometer reads 1000. What happens when the hydrometer is placed in a liquid with a specific gravity greater than that of water?
The float rises higher, and the scale shows a reading greater than 1000
In experiments measuring applied forces, three types of friction are identified based on how objects interact.
Starting or static friction
Sliding friction
Rolling friction
Speed measures how fast an object moves, calculated as distance divided by time, while velocity includes both speed and direction. An airplane flies at a constant speed of 200 mph in a circular pattern for 2 hours. How does this affect its velocity over time?
Velocity changes constantly because the direction keeps changing
The BTU is a unit of heat energy commonly used in aviation maintenance to discuss engine thermal efficiencies and the heat content of fuels. How is one BTU defined?
The heat required to raise 1 lb of water 1 °F; it’s practical for evaluating aviation fuel energy.
Pascal’s Law explains how hydraulic pressure can perform work in systems like aircraft brakes or landing gear. What is the main principle of Pascal’s Law that enables this functionality?
Pressure set up in a fluid acts equally in all directions
To determine the density of a liquid, you need its weight and volume. For example, a liquid filling a container that is 4 ft long, 3 ft wide, and 2 ft deep (volume of 24 ft³) weighs 1,497.6 lb. Dividing the weight by the volume gives a density of 62.4 lb/ft³, which matches the density of water at 4 °C, a common standard. How would an increase in temperature affect the density of this liquid?
The density would decrease because the volume increases while the weight stays the same
Power is the rate at which work is done, calculated as Power = Force × Distance ÷ Time. One horsepower (hp) is defined as 550 foot-pounds per second (ft-lb/s) or 33,000 foot-pounds per minute (ft-lb/min). Suppose a crane lifts a 12,000-lb aircraft component 5 ft in 1 minute. What is the power required in foot-pounds per minute, and how many horsepower does this correspond to?
60,000 ft-lb/min; 1.82 hp
Forces like tension, compression, torsion, bending, shear, and strain affect objects in distinct ways. A turbine shaft in a turbofan engine experiences a stress when torque is applied to drive the compressor. What type of force is primarily acting on the shaft, and what stresses does it involve?
Torsion; it involves tension and compression acting at angles
Heat energy, such as the 18,900 BTU in one pound of aviation gasoline, can be transferred in different ways within an aircraft engine system. During operation, the engine’s heat moves from the combustion chamber to surrounding components. What method of heat transfer occurs when heat passes through the metal walls of the chamber to the outer casing?
Conduction; heat moves through direct contact between solid materials
The speed of sound varies depending on the density and properties of the medium it travels through. Which set of states of matter is from slowest to fastest speed of sound?
Gases, liquids, solids