0.21kg pine cone falls 14 m to the ground, where it lands with a speed of 13 m / s. (a) with what speed would the pine cone have landed if there had been no air resistance? (b) did air resistance do positive work, negative work, or zero work on the pine cone? explain

An uplifted block of rock between two normal faults

The particles that are found in the nucleus of an atom are

It may seem strange that the selected velocity does not depend on either the mass or the charge of the particle. (for example, would the velocity of a neutral particle be selected by passage through this device? ) the explanation of this is that the mass and the charge control the resolution of the device--particles with the wrong velocity will be accelerated away from the straight line and will not pass through the exit slit. if the acceleration depends strongly on the velocity, then particles with just slightly wrong velocities will feel a substantial transverse acceleration and will not exit the selector. because the acc