Torque will produce rotation
Answer:
What is most widely accepted today is the giant-impact theory. It proposes that the Moon formed during a collision between the Earth and another small planet, about the size of Mars. The debris from this impact collected in an orbit around Earth to form the Moon.
Total work energy on the input side is WE = Fs; where F is a force acting on a mass to push it s distance. This is the so-called work function. Let fs = we, which is the work energy (useful energy) attained as output when WE is input.
<span>From the conservation of energy WE = Fs = fs - kNs = Total Output energy. Net force f = F - kN where kN is friction force acting against the pushing (input) force F. In the real world, there is always friction at some level. That is kN > 0 always. </span>
<span>Thus Fs = (F - kN)s; kNs = the energy lost to friction where k is the friction coefficient and N is the normal force on the surface(s) where the friction is generated. By definition, efficiency = fs/Fs = useful work/work input. Clearly fs = Fs - kN < Fs . Thus efficiency = fs/Fs < 1.00, which means output fs < Fs the input whenever kN > 0, which in the real world it always is. </span>
<span>The short answer is...output is always less than input because of friction and, sometimes, other losses like wind drag (which is a form of friction anyway).</span>
No. You have to lose a lot of momentum to slow down enough to survive the impact (obviously depending on the height of the building). In your scenario, you can only transfer that momentum to the chair, by pushing it downward with your legs.
Let's say you jump off a 10 metre tall building and have a mass of 75 kg. You will be travelling at about 14 m/s just before impact, with a momentum of 1050 kgm/s. You want to reduce that momentum to around 750 kgm/s (equivalent to falling from a height of 5 m, which is probably survivable and may leave you able to walk away), so you have to transfer 300 kgm/s of momentum to the chair just by pushing it with your legs. For a 10 kg chair that means accelerating it to 30 m/s (in addition to the 14 m/s velocity the chair and you are already falling at), which is rather difficult.
You'd probably be better off landing on the chair and hoping that the chair breaking absorbs enough of the impact.