when you blow across the top of a soda bottle it acts like a closed pipe. if it creates a fundamental frequency of 680 Hz, how deep is the bottle? (Speed of sound = 343 m/s) (Unit = m)

In the derivation of rrkm theory, a factor of 1/2 is introduced when equalizing the rates of formation and decomposition of activated complex as keal-hr) = ko this is clearly against the assumption of transition state theory that states all the activated complex in the transition state iss going to the product. find the reason why this factor is introduced here.

When you push downward on a book at rest on a table, you feel an upward force. does this force depend on friction? defend your answer.

Electromagnetic induction. a coil of wire contains n turns and has an electrical resistance r. the radius of each turn is a. initially, inside the coil there exists a uniform magnetic field of magnitude b0 parallel to the axis of the coil. the magnetic field is then reduced slowly. the current induced in the coil is i. how long does it take for the magnitude of the uniform field to drop to zero?