Physics

The time required to decay half of the total amount of atoms present in a radioactive element is called half-life. 

The frictional force that is experienced by an object when it moves in a liquid or a gaseous substance is called fluid friction. When an object moves in a fluid; i.e. liquid or gas the friction acts is called fluid friction.

The angle of in the denser medium for which the angle of refraction in the rarer medium becomes 90° when light rays travel from denser to a rarer medium is called the critical angle.

Consider a point P located at P(x,y). A positive 6m in the x-direction and positive 4m in the y-direction, this is the position of point P. So, the position is a place where someone or something is located or has been put. The position is a vector quantity because it has direction.

Stress is the pressure on tension exerted on a material object. According to Hook’s law, stress = constant × strain

In the realm of physics, a reference frame serves as an indispensable tool for describing and measuring motion. It’s akin to a virtual viewpoint or perspective that allows us to pinpoint the position and motion of objects in space. To grasp concepts like speed, velocity, and acceleration, we depend entirely on reference frames.

When two or more forces acting on an object produce zero resultant force, i.e. the object has no acceleration; we say that the forces are balanced.

A fundamental unit of measurement is a defined unit that cannot be described as a function of other units.