Afreight car moves along a frictionless level railroad track at constant speed. the freight car is open on the top. a large load of sand is suddenly dumped into the freight car. what happens to the speed of the freight car?

Most short-period comets do not have randomly oriented orbits because

Often called simply "velocity," this is the velocity of an object at a particular moment in time.

An important dimensionless parameter concerned with very high-speed flow is the mach number, defined as v/c, where v is the speed of the object such as an airplane or projectile, and c is the speed of sound in the fluid surrounding the object. for a projectile traveling at 1170 mph through air at 50 ˚f and standard atmospheric pressure, what is the value of the mach number?