Equations of motion force the object exerts. Replacing momentum by mass times velocity, the law is also written more famously as since is a constant in Newtonian mechanics. Newton's second law applies to point-like particles, and to all points in a rigid body. They also apply to each point in a mass continua, like deformable solids or fluids, but the motion of the system must be accounted for, see material derivative. In the case the mass is not constant, it is not sufficient to use the product rule for the time derivative on the mass and velocity, and Newton's second law requires some
Escape velocity velocity and the escape velocity. With a circular orbit, escape velocity is times the orbital speed. Thus the total escape velocity formula_29 when leaving one body orbiting a second and seeking to escape them both is, under simplified assumptions: where formula_31 for circular orbits. The last two columns will depend precisely where in orbit escape velocity is reached, as the orbits are not exactly circular (particularly Mercury and Pluto). Let "G" be the gravitational constant and let "M" be the mass of the earth (or other gravitating body) and "m" be the mass of the escaping body or projectile. At