Why sound can be hear more distinctly at a greater distance over water surface ?

A short sighted person can see objects most distinctly at a distance of 16 cm. If he wears spectacles at a distance of 1 cm from the eye, then their focal length to see distinctly at a distance of 26 cm

Can displacement be greater than distance?

A man suffering from short sight is unable to see objects distinctly at a distance greater than 2 m. The power of lens required to correct this deffect should be

Why is mercury perferred as a barometric substance over water?

A man is swimming at a depth d in a sea at a distance L (gt gt d) from a ship (S). An explosion occurs in the ship and after hearing the sound the man immediately moves to the surface. It takes 0.8 s for the man to rise to the surface after he hears the sound of explosion. 0.2 s after reaching the surface he once again hears a sound of explosion. Calculate L. Give: speed of sound in air =340 ms^(-1) , Bulk modulus of water =2xx10^(9) Pa

When a pipe, through which water is flowing out, is partially closed with a finger, the water stream coming out falls to a greater distance from the pipe. Why?

Which will cause more friction : a rough surface or a smooth surface ? Why ?