A car is traveling at the posted speed limit of 6.70 m/s (15 miles/h) in a school zone. The car passing a school bus when a child darts out from in front of the bus. The car is 10.0 m from the child when the driver of the car applies the brakes. The car decelerates at a constant rate of 4.00 m/s2 until coming to a halt. Calculate the
(a) distance of the car travels while decelerating and
(b) distance required to stop if the car is initially traveling at 13.4 m/s (30.0 miles/h).

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