1. Work is defined as the transfer of energy from one form to another. It is typically measured in units of joules (J) or foot-pounds (ft-lb).
2. Energy is defined as the ability to do work. It can be classified into several forms, including kinetic energy (the energy of motion), potential energy (the energy of position or configuration), and thermal energy (the energy of heat).
3. Power is defined as the rate at which work is done or energy is transferred. It is typically measured in units of watts (W) or horsepower (hp). Power is a measure of the rate at which energy is transferred or work is done, and is calculated by dividing the amount of work done or energy transferred by the time taken to do the work or transfer the energy.

1. The principle of work is a fundamental principle of mechanics that states that the work done by a force on an object is equal to the product of the force and the displacement of the object in the direction of the force. This principle is commonly expressed as the following equation:

Work = Force * Displacement

1. Limiting efficiency is the maximum efficiency that can be achieved by a machine under a given set of operating conditions. This efficiency is determined by the design of the machine and the materials used in its construction, and is typically expressed as a percentage.

1. Limiting friction force (also known as maximum static friction force) is the maximum force that can act between two surfaces in contact without causing the surfaces to move relative to each other. This force is determined by the normal force acting on the surfaces and the coefficients of static and kinetic friction between the surfaces.
2. Angle of repose is the angle at which a pile of granular material (such as sand or gravel) forms a stable slope. This angle is determined by the forces acting on the particles in the pile, including the weight of the particles, the forces of friction between the particles, and any other external forces acting on the pile. The angle of repose is typically measured with respect to the horizontal, and is equal to the angle at which the pile of material will remain stable without collapsing.

Newton’s second law of motion states that the rate of change of momentum of a body is directly proportional to the force applied to the body and occurs in the direction in which the force is applied. This law is commonly expressed as the following equation:

F = ma

where F is the force applied to the body, m is the mass of the body, and a is the acceleration of the body. This equation shows that the greater the mass of the body, the greater the force required to accelerate it, and the greater the acceleration of the body, the greater the force required to maintain it.

A flywheel is a mechanical device that is used to store rotational energy. It consists of a heavy disk or wheel that is mounted on a shaft and rotated at a high speed. The flywheel acts as a buffer, smoothing out fluctuations in the input power to a machine and providing a steady flow of energy to the machine. This helps to maintain the machine’s speed and prevent it from stalling or slowing down due to changes in the load.

A speed governor is a device that is used to control the speed of a machine. It consists of a set of weights or springs that are attached to the shaft of the machine and act to oppose any changes in the speed of the shaft. The speed governor works by detecting changes in the speed of the shaft and using the weights or springs to apply a force that counteracts the change in speed. This helps to maintain the speed of the machine within a specified range, regardless of changes in the load.

The main difference between a flywheel and a speed governor is that a flywheel stores rotational energy, while a speed governor controls the speed of a machine. A flywheel is typically used to provide a steady flow of energy to a machine, while a speed governor is used to maintain the speed of a machine within a specified range.