Can there be a physical quantity  which has no unit and dimension? Can a quantity have a unit without dimensions?

Ohh I got it:

Q: Why is sand thrown on roads covered with snow?

Sorry for the squeezed equation. A new note will be ready.

The foods we eat, the air we breathe, cleaning chemicals, our emotions and literally every object that we can see or touch, love, jealousy, infatuation and all share in chemistry. For all living things to function and survive, their bodies perform various chemical processes.

That is correct, @UNKNOWN! 7.00 indeed has three significant figures.

Sorry about the typo. 

Dimension of angle is [M⁰L⁰T⁰], So, the A and C have dimension [L]. Since, x is a distance and t is time, B and D have dimensions [L^-1] and [T^-1] . Their ratio has dimension[L^-1 T].

Precision is a measure of statistical variability. It describes random errors which is caused by permanent, unpredictable fluctuations of measuring instrument. In other words, it basically describes closeness of the measured values.  For example, you used normal ruler to measure length of certain object and now you have used a Laser Interferometer to measure the same object . Of course, there will be more precision in latter one as there will be more fluctuations in previous one, which...

1) Two physical quantities can only be equated if they have the same dimensions.

 2) Two physical quantities can only be added if they have the same dimensions.

 3) The dimensions of the multiplication of two quantities is given by the multiplication of the dimensions of the two quantities.

The order of magnitude of a physical quantity is its magnitude in powers of ten when the physical quantity is expressed in powers of ten with one digit to the left of the decimal.

Orders of magnitude are generally used to make very approximate comparisons and reflect very large differences.

A dimensionally correct equation need not be actually correct, but a dimensionally incorrect equation is necessarily wrong.

The sky is blue due to a phenomenon called Raleigh scattering. This scattering refers to the scattering of electromagnetic radiation (of which light is a form) by particles of a much smaller wavelength.

It has been raining all this evening

The physics behind the domino effect, also known as the domino theory, is based on the principles of transfer of energy and momentum. When one domino falls, it transfers its energy to the next domino through the process of collision, causing the next domino to fall as well. This transfer of energy and momentum continues down the line of dominoes, resulting in a chain reaction.

The domino effect can be explained using the principles of Newton's laws of motion. According to the first law, an...