An aeroplane’s velocity is doubled.
(a) What happens to its momentum ? Is the law of conservation of momentum obeyed ?
(b) What happens to its kinetic energy ? Is the law of conservation of energy obeyed ?
(a) The momentum of aeroplane will be doubled. Yes, the law of conservation of momentum will also be obeyed because increase in momentum of aeroplane is simultaneously accompanied by increase in momentum of exhaust gases.
(b) K.E. becomes four times.
Yes, the law of conservation of energy is obeyed with the increase in K.E. coming from the chemical energy of fuel, i.e., from the burning of its fuel