According to Newton's first law of motion, an object at rest will remain at rest, and an object in motion will continue moving at a constant velocity, unless acted upon by an unbalanced force. In static equilibrium, there are no unbalanced forces acting on the object, resulting in a net force of zero.

The SI unit of force is the Newton (N), named after Sir Isaac Newton. It is defined as the force required to accelerate a mass of one kilogram at a rate of one meter per second squared.

Work is a scalar quantity that measures the energy transferred to or from an object by a force. It is calculated as the dot product of the force vector and the displacement vector, which is the distance moved in the direction of the force.

When a spring is stretched or compressed, it stores potential energy. This energy is due to the elastic properties of the spring, which tend to restore it to its original shape when the force is removed.

Thermal conductivity is a measure of a material's ability to transfer heat through conduction. It is defined as the amount of heat transferred through a unit area of the material per unit time per unit temperature gradient.

Specific heat capacity is a measure of the amount of heat required to raise the temperature of a unit mass of a substance by one degree Celsius. It is a characteristic property of the substance and is used to calculate the amount of heat required to change the temperature of a given mass of the substance.

The ideal gas law, also known as the general gas equation, states that the pressure, volume, and temperature of a gas are directly proportional to each other. This means that if one of these variables changes, the other two will also change in a proportional manner.

The coefficient of restitution is a dimensionless quantity that measures the elasticity of a collision. It is defined as the ratio of the relative velocity of separation to the relative velocity of approach of the colliding objects. A coefficient of restitution of 1 indicates a perfectly elastic collision, while a coefficient of restitution of 0 indicates a perfectly inelastic collision.

The moment of inertia of a rigid body is a measure of its resistance to rotation. It is defined as the sum of the products of the masses of the particles of the body and the squares of their distances from the axis of rotation. A larger moment of inertia indicates a greater resistance to rotation.

The gyroscopic effect is a phenomenon that occurs when a spinning object experiences a torque that is perpendicular to its axis of rotation. This torque causes the axis of rotation to precess, or wobble, around the direction of the applied torque. Additionally, the spinning object may also experience nutation, which is a small, periodic oscillation of the axis of rotation around the direction of precession.

The principle of superposition states that when multiple waves overlap in a medium, the resulting displacement at any point is the sum of the displacements that would be caused by each wave individually. This principle is fundamental to understanding wave phenomena such as interference and diffraction.

The Doppler effect is the change in frequency of a wave in relation to an observer or a source. When the observer or source is moving relative to the wave, the frequency of the wave changes. This effect is commonly observed in sound waves, where the pitch of a sound changes as the source or observer moves.

Young's modulus is a measure of the stiffness of a material. It is defined as the ratio of stress to strain in the elastic region of the material's behavior. A higher Young's modulus indicates a stiffer material, meaning it resists deformation under stress.

Poisson's ratio is a measure of the lateral strain to axial strain ratio of a material. It is defined as the negative ratio of lateral strain to axial strain when a material is subjected to uniaxial stress. A Poisson's ratio of 0.5 indicates that the material is incompressible, meaning its volume does not change under uniaxial stress.

The ultimate tensile strength of a material is the maximum stress it can withstand before it breaks. It is a measure of the material's strength and is commonly used in engineering design to ensure that materials can withstand the stresses they will encounter in service.