An electron has a mass of 0.511 MeV/c2. Calculate the speed, momentum, and total energy of a 0.991 MeV electron.

A) soundwaves travel through a vacuum

Free body diagram: force of gravity  pointing down, with normal force  with same magnitude, pointing up.in horizontal direction, there is only friction force  , pointing opposite to direction of motion.so the net force comes from friction force (gravity and normal cancel out).===normal force is  friction force is, with  therefore,  andwe have kinematic equationif initial velocity  final velocity acceleration  then16.989 m, or 20 m for one significant figure.