Angle of reposeThe angle of repose, or critical angle of repose, of a granular material is the steepest angle of descent or dip relative to the horizontal plane on which the material can be piled without slumping. At this angle, the material on the slope face is on the verge of sliding. The angle of repose can range from 0° to 90°. The morphology of the material affects the angle of repose; smooth, rounded sand grains cannot be piled as steeply as can rough, interlocking sands.
Simple machineA simple machine is a mechanical device that changes the direction or magnitude of a force. In general, they can be defined as the simplest mechanisms that use mechanical advantage (also called leverage) to multiply force. Usually the term refers to the six classical simple machines that were defined by Renaissance scientists: Lever Wheel and axle Pulley Inclined plane Wedge Screw A simple machine uses a single applied force to do work against a single load force.
FrictionFriction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding or grinding against each other. Types of friction include dry, fluid, lubricated, skin, and internal – an incomplete list. The study of the processes involved is called tribology, and has a history of more than 2,000 years. Friction can have dramatic consequences, as illustrated by the use of friction created by rubbing pieces of wood together to start a fire.Mechanical advantageMechanical advantage is a measure of the force amplification achieved by using a tool, mechanical device or machine system. The device trades off input forces against movement to obtain a desired amplification in the output force. The model for this is the law of the lever. Machine components designed to manage forces and movement in this way are called mechanisms. An ideal mechanism transmits power without adding to or subtracting from it.
Mechanical energyIn physical science, mechanical energy is the sum of macroscopic potential and kinetic energies. The principle of conservation of mechanical energy states that if an isolated system or a closed system is subject only to conservative forces, then the mechanical energy is constant.
ForceInfluence that can change motion of an objectIn physics, a force is an action that can cause an object to change its velocity or its shape, or to resist other forces, or to cause changes of pressure in a fluid. In mechanics, force makes ideas like pushing or pulling mathematically precise. Because the magnitude and direction of a force are both important, force is a vector quantity (force vector).
Work (physics)In science, work is the energy transferred to or from an object via the application of force along a displacement. In its simplest form, for a constant force aligned with the direction of motion, the work equals the product of the force strength and the distance traveled. A force is said to do positive work if it has a component in the direction of the displacement of the point of application.Conservation of energyThe law of conservation of energy states that the total energy of an isolated system remains constant; it is said to be conserved over time. In the case of a closed system, the principle says that the total amount of energy within the system can only be changed through energy entering or leaving the system. Energy can neither be created nor destroyed; rather, it can only be transformed or transferred from one form to another.WedgeA wedge is a triangular shaped tool, a portable inclined plane, and one of the six simple machines. It can be used to separate two objects or portions of an object, lift up an object, or hold an object in place. It functions by converting a force applied to its blunt end into forces perpendicular (normal) to its inclined surfaces. The mechanical advantage of a wedge is given by the ratio of the length of its slope to its width.
Vertical and horizontalIn astronomy, geography and related sciences, a line or plane passing by a given point is said to be vertical if it contains the local gravity direction at that point. Conversely, a line or plane is said to be horizontal (or leveled) if it is perpendicular to the vertical at a given point.
Vertical positionVertical position or vertical location is a position along a vertical direction (the plumb line direction) above or below a given vertical datum (a reference level surface, such as mean sea level). Vertical distance or vertical separation is the distance between two vertical positions.*As an Amazon Associate I earn from qualifying purchases.