why 0!=1 in 30 Seconds. (Shortest 0 factorial proof) #shorts

A man sets his watch by the noon-whistle of a factory at a distance of 1.5 kilometers. By how many seconds is his watch slower than the clock of the factory? (Velocity of sound in air is 332 m s^(-1) )

An X-ray tube operated at 30 kV emits a continuous X-ray of short wavelength limit lambda =0.414 Å . The value of Planck's constant is

The deposition of 1.0g of which element from its molten chloride requires the shortest time at a current of 1A?

The end correction of a resonance colume is 1.0 cm. If the shortest length resonating with the tuning fork is 15.0 cm the next resonating length will be

Find the equations of the lines joining the following pair of vertices and then find its shortest distance between the lines : (i) (0,0,0), (1,0,2) (ii) (1,3,0), (0,3,0).