Comic-strip hero superman meets an asteroid in outer space, and hurls it at 850 m/s, as fast as a bullet. the asteroid is three
thousand times more massive than superman. in the strip, superman is seen at rest after the throw. taking physics into account, what would be his recoil velocity?
Before the asteroid is threw, the total momentum is zero,
since neither Superman nor the asteroid are moving.
Conservation of momentum commands the total momentum after the astronaut is threw
must be zero too. This means that Superman's backward momentum afterward throwing
the asteroid is equivalent to the asteroid forwards momentum, in size.
Momentum is mass times velocity. We know the mass of the asteroid is 1000M and
its velocity is 850 m/s, so its momentum is
(1000M)(850 m/s) = 850,000M m/s.
So to get the answer: dividing by
Superman's mass, M, gives his recoil velocity o 850,000 m/s.
All potential and kinetic energy is transferred into heat. Therefore keeping the law of conservation of energy valid. No energy is created nor destroyed only changing shape.
