The energy produced by mechanical means is called mechanical energy. It has two forms: (i) Kinetic energy (ii) Potential energy. Kinetic energy The energy possessed by a body by virtue of its motion is called its kinetic energy. A moving object can do work. The amount of work that a moving object can do before … Read more
As W = FS ∴ 1 unit work = 1 unit force × 1 unit distance Thus, unit work is the amount of work done when a unit force displaces a body through a unit distance in the direction of the force. Absolute units of work. Work done is said to be one absolute unit … Read more
Every measurement is done with the help of some instrument. While making the measurement, some uncertainty gets introduced in the measurement. As a result, the measured value is always somewhat different from the actual or true value. The error in a measurement is equal to the difference between the true value and the measured value … Read more
The order of magnitude of a physical quantity is that power of 10 which is closest to its magnitude. It gives an idea about how big or how small a given physical quantity is. To determine the order of magnitude of a number N, we first express it as N = n × 10x. If … Read more
A complete set of units which is used to measure all kinds of fundamental and derived quantities is called a system of units. Some of the commonly used systems of units are as follows : (i) cgs system: It was set up in France. It is based on centimetre, gram and second as the fundamental … Read more
Mass: The mass of a body is the quantity of matter contained in it. It is a basic property of matter. It does not depend on the temperature, pressure or location of the body in space. The SI unit of mass is kilogram (kg). Weight: The weight of a body is the force with which … Read more
Laser is used for this method. The word laser stands for light amplification by stimulated emission of radiation. Laser is a source of very intense, highly monochromatic (of one wavelength) and highly directional beam of light. A laser beam is sent towards the moon and its reflected pulse is received. If ‘t’ is the time … Read more
The standard amount of a physical quantity chosen to measure the physical quantity of the same kind is called a physical unit. Desirable characteristics of a physical unit: 1. It should be well-defined. 2. It should be of convenient size, i.e., neither too small nor too large in comparison with the measurable physical quantity. 3. … Read more
All those quantities which can be measured directly or indirectly and in terms of which the laws of physics can be expressed are called physical quantities. For example, length, mass, temperature, speed, force, electric current, etc. The physical quantities are the building blocks of physics in terms of which the basic laws of physics can … Read more
