Nature of Matter and Chemical Compounds

<p>Friction is a resistance to motion (A)</p> Signup and view all the answers

<p>Efficiency = Work out / Work in X 100 (B)</p> Signup and view all the answers

<p>The object is in equilibrium (A)</p> Signup and view all the answers

<p>MA = Load/Effort (D)</p> Signup and view all the answers

<p>First-class lever (A)</p> Signup and view all the answers

<p>Stress (B)</p> Signup and view all the answers

<p>Tension (D)</p> Signup and view all the answers

<p>The material returns to normal (C)</p> Signup and view all the answers

<p>Abrupt or uneven temperature changes (A)</p> Signup and view all the answers

<p>Bend it upwards and downwards (D)</p> Signup and view all the answers

<p>Deceleration (D)</p> Signup and view all the answers

<p>Acceleration is directly proportional to force and inversely proportional to mass. (A)</p> Signup and view all the answers

<p>Inertia (B)</p> Signup and view all the answers

<p>It continuously changes the direction of the object's motion. (A)</p> Signup and view all the answers

<p>Resonance (D)</p> Signup and view all the answers

<p>Periodic motion (B)</p> Signup and view all the answers

<p>Wave energy (B)</p> Signup and view all the answers

<p>Metal fatigue (B)</p> Signup and view all the answers

<p>Alternating compression and tensile stresses (D)</p> Signup and view all the answers

<p>It is determined by height, gravity, and density. (C)</p> Signup and view all the answers

<p>Mass per unit volume (A)</p> Signup and view all the answers

<p>If it displaces a volume of fluid equal to its own weight (A)</p> Signup and view all the answers

<p>Pressure is exerted equally in all directions. (A)</p> Signup and view all the answers

<p>Speed measures distance traveled over time, while velocity measures displacement over time. (A)</p> Signup and view all the answers

<p>Liquids have a consistent density, while gases do not. (C)</p> Signup and view all the answers

<p>The density of a substance compared to the density of water. (D)</p> Signup and view all the answers

<p>Matter in which all molecules are identical and comprised of different atoms in exact proportions. (B)</p> Signup and view all the answers

<p>An atom that loses an electron becomes positively charged. (C)</p> Signup and view all the answers

<p>It transforms into a liquid without changing in volume. (D)</p> Signup and view all the answers

<p>Liquids have a definite volume but not a definite shape. (C)</p> Signup and view all the answers

<p>The maximum number of electrons in a shell equals $2n^2$. (C)</p> Signup and view all the answers

<p>Molecules in liquids are partially bonded together. (B)</p> Signup and view all the answers

<p>A push or pull that can produce a change in a body's state of motion. (A)</p> Signup and view all the answers

<p>All components in a mixture retain their individual characteristics. (B)</p> Signup and view all the answers

<p>As the speed of a moving fluid increases, the pressure decreases. (D)</p> Signup and view all the answers

<p>Venturi Effect (B)</p> Signup and view all the answers

<p>Pressure difference between upper and lower surfaces (C)</p> Signup and view all the answers

<p>Energy can only be converted from one form to another. (C)</p> Signup and view all the answers

<p>Conduction (A)</p> Signup and view all the answers

<p>In a flowing liquid or gas (B)</p> Signup and view all the answers

<p>Calorie (D)</p> Signup and view all the answers

<p>Joule (D)</p> Signup and view all the answers

<p>The speed of the aircraft (B)</p> Signup and view all the answers

<p>Total pressure (A)</p> Signup and view all the answers

<p>The fluid's temperature (B)</p> Signup and view all the answers

<p>The kinetic energy of the airflow impacting the aircraft (B)</p> Signup and view all the answers

<p>It increases by four times (C)</p> Signup and view all the answers

<p>Where the fluid expands again (B)</p> Signup and view all the answers

<p>It is necessary for generating lift (A)</p> Signup and view all the answers

<p>A second probe placed out of the airflow (D)</p> Signup and view all the answers

<p>A liquid has a fixed volume and a free surface. (B)</p> Signup and view all the answers

<p>The resistance of a fluid to flow. (C)</p> Signup and view all the answers

<p>A gas has no fixed volume and can fill the complete vessel. (D)</p> Signup and view all the answers

<p>It provides adequate resistance to airflow to generate aerodynamic force. (D)</p> Signup and view all the answers

<p>It causes the plane of rotation to deflect in the direction of rotation. (D)</p> Signup and view all the answers

<p>The change in viscosity with temperature variations. (D)</p> Signup and view all the answers

<p>It provides necessary resistance for generating aerodynamic forces. (C)</p> Signup and view all the answers

<p>It flows and deforms permanently. (C)</p> Signup and view all the answers

<p>Viscosity decreases (D)</p> Signup and view all the answers

<p>It ensures minimal changes in properties across a range of temperatures (B)</p> Signup and view all the answers

<p>The region of reduced speed close to a surface due to friction (A)</p> Signup and view all the answers

<p>Curvature can minimize drag if flow remains attached (B)</p> Signup and view all the answers

<p>The tendency of a fluid to stick to a solid surface and flow around it (B)</p> Signup and view all the answers

<p>Viscosity increases due to increased momentum exchange (B)</p> Signup and view all the answers

<p>When the flow detaches from the surface due to shape curvature (A)</p> Signup and view all the answers

<p>It reduces the area over which drag acts (C)</p> Signup and view all the answers

Anything that occupies space and has mass; exists as solid, liquid, or gas.

Simplest form of matter, made of atoms.

Basic unit of an element, made of protons, neutrons, and electrons.

Matter formed by combining different elements in fixed proportions.

Definite shape and volume; atoms tightly packed.

Definite volume, indefinite shape; flows to fill container.

Indefinite shape and volume; atoms move freely.

Something that can change the motion of an object.

The top and bottom surfaces of an aircraft wing experience alternating compression and tensile stresses due to air pressure differences.

Both liquids and gases are fluids, but liquids are incompressible (constant density) while gases are compressible.

The pressure exerted by a column of liquid is determined by the height of the column, gravity, and the density of the fluid.

Density is the mass per unit volume of a substance, essentially how much stuff is packed into a given space.

A state where the resultant of all forces acting on an object is zero, causing no change in its motion (rest or constant velocity).

Specific gravity compares the density of a liquid to the density of water. It tells you how much heavier or lighter the liquid is compared to water.

An object placed in a fluid will displace a volume of fluid equal to its own volume, and experience an upward buoyant force equal to the weight of the fluid displaced.

A device that makes work easier by changing the direction or magnitude of a force.

The ratio of the load (output) to the effort (input) force. A higher MA means less effort is needed to move a load.

The upward force acting on a submerged object, equal to the weight of the fluid displaced by the object.

When pressure is applied to a confined liquid, the liquid exerts an equal pressure at right angles to the container.

The force acting through an area of a solid material (force per unit area).

The deformation of a material in response to stress. It's how much a material changes shape.

For small strains, the strain (deformation) of a material is directly proportional to the applied stress.

Two equal and opposite parallel forces acting on a body at different points, resulting in a turning effect (moment).

Internal stress in a material caused by uneven temperature changes.

The rate of change in velocity, meaning an object's speed or direction is changing.

Negative acceleration, meaning an object is slowing down.

The tendency of an object to resist changes in its motion.

An object at rest stays at rest, and an object in motion stays in motion at a constant velocity unless acted upon by a net force.

The acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass.

For every action, there's an equal and opposite reaction.

A force that acts towards the center of a circular path, keeping an object moving in a circle.

The transfer of energy between two objects with the same natural frequency, causing one object to vibrate more strongly.

A force that resists motion when two surfaces rub against each other. It can be thought of as a 'brake' on movement.

A number that describes how much friction exists between two surfaces. Higher values mean more friction.

The ratio of useful work output to the total energy input. Friction reduces efficiency because it converts energy into heat.

A measure of how much motion an object has in a straight line. It depends on the object's mass and velocity.

A measure of how much an object is rotating. It depends on the object's mass, shape, and speed of rotation.

The pressure associated with the movement of a fluid. It increases with the speed of the fluid.

States that as the speed of a fluid increases, the pressure within the fluid decreases.

The reduction of static pressure through a constriction in a fluid flow.

The air passing over the top surface of a wing moves at a higher velocity, creating lower pressure above the wing, resulting in upward lift.

Energy related to heat, its transfer, or loss.

Heat transfer through direct contact between two objects at different temperatures.

Heat transfer through the movement of fluids (liquids or gases).

A unit of heat energy required to raise the temperature of one gram of water by one degree Celsius.

The resistance of a fluid to flow. A fluid with a lower viscosity flows easily, while a fluid with a higher viscosity is thicker and resists flow.

Measures how much a fluid's viscosity changes with temperature. A high viscosity index means the fluid's viscosity changes little with temperature.

Air must have some viscosity to create resistance, otherwise there would be no aerodynamic force.

A liquid's free surface forms when it is in a container. It is the visible upper boundary of the liquid.

Gases do not have a free surface because they expand to fill their container, leaving no visible boundary.

Liquids occupy a fixed volume, take the shape of their container, and form a free surface.

Gases have no fixed volume, expand to fill their container, and do not form a free surface.

The pressure exerted by the weight of the atmosphere above a point, acting equally in all directions.

The sum of static pressure and dynamic pressure.

Total pressure is the pressure measured in the airflow, including both static and dynamic pressures. Static pressure is the pressure measured at a point at rest in the air, without considering the airflow.

The curved upper surface of a wing forces air to travel faster, resulting in lower pressure above the wing, creating lift.

It measures airspeed by comparing total pressure (measured by a tube facing the airflow) and static pressure (measured by a hole perpendicular to the airflow).

For most liquids, viscosity (resistance to flow) decreases as temperature increases. This is because molecules are less tightly bound at higher temperatures, leading to less friction between them.

A low viscosity index for lubricating oils is desirable because it means the oil's properties remain relatively stable over a wide temperature range.

The viscosity of a gas increases with temperature. This is due to increased momentum exchange between gas molecules as they move faster at higher temperatures.

The tendency of a fluid jet to follow a curved surface. This happens because the fluid is deflected towards the surface, creating a pressure difference.

The region near a surface where fluid flow is slowed due to friction.

Designing shapes that minimize air resistance by allowing smooth flow around an object.

The force that opposes the motion of an object through the air, caused by friction and pressure differences.

Attached flow occurs when a fluid sticks to a curved surface, while separated flow happens when the fluid detaches from the surface, creating high resistance.