Hi everyone! Ok, so we have a bird which is flapping its wings. Avg speed of air displaced is v. Area of wings is A. Density of air is p. Thus mass of air displaced per second is vAp. This is ok. However, according to conservation of momentum, (vAp)(v)=mg, where m is mass of bird Also however, according to Newton's Third Law, Force everted by bird on air=Force exerted on air by bird, (vAp)(g)=mg ??? Is there a mistake in my understanding??? Thanks.