a person left on a frictionless surface can get away from it by blowing air out of his mouth or by throwing some objectin a direction opposite to the direction in which he wants to move.how????
Both the things will work!
He can even blow air from his mouth or throw any object in the direction opposite to the direction he wants to head.
It happens due to since there is no external force acting on the man in the x direction the total momentum will be consedverd in that direction !
That is why due to conservation of momentum :
Mv = (M-m)u1+ mu2
Where
v = initial velocity of the man = that is zero.
u1 is the velocity of the man after blowing or throwing the object.
u2 is the velocity of the air of the object!
m = mass of the air blown or the object thrown
0 = (M-m)u1+ mu2
So from the equation we can see that he is supposed to throw the object in opposite direction.
Blowing air will not be that much efficient but throwing object is more efficent!
He can even blow air from his mouth or throw any object in the direction opposite to the direction he wants to head.
It happens due to since there is no external force acting on the man in the x direction the total momentum will be consedverd in that direction !
That is why due to conservation of momentum :
Mv = (M-m)u1+ mu2
Where
v = initial velocity of the man = that is zero.
u1 is the velocity of the man after blowing or throwing the object.
u2 is the velocity of the air of the object!
m = mass of the air blown or the object thrown
0 = (M-m)u1+ mu2
So from the equation we can see that he is supposed to throw the object in opposite direction.
Blowing air will not be that much efficient but throwing object is more efficent!