During the experiment it is determined that, as the cart rolls between two points on the track, the work done on the cart by the hanging masses and other forces present is 0.91 J. At the initial time of observation the cart moves with speed 0.61 m/s. Determine the speed at the second point of observation. The mass of the cart is 0.80 Kg.

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