momentum problem for physics?

Question

I am having trouble with this momentum question..

The momentum of an apple falling to the ground is not conserved because the external force of gravity acts on it. But the momentum is conserved in a larger system. Explain how.

Answer 1

The external force of gravity (acting mainly from Earth) becomes internal for the system Earth + apple, and for this system the momentum becomes conserved.
Thus, the Earth is spinning around itself together with the apple tree and the apple on it. When the apple falls to the Earth, the distance between the two masses becomes smaller, hence the speed of spinning becomes grater, and their momentum remains the same.
It is like a sportsman in figure skating spins faster after pressing his hands close to his body.

Answer 2

Conservation of momentum applies to a closed system not individual objects. Remember the old billiard ball problem.

Answer 3

the respond is interior the hint itself P preliminary = P very final The preliminary momentum of pupil and jacket is 0 as they're the two not shifting the suitable momentum is the momentum of boy and jacket after he throws the jacket 0 = m1x v1 + m2 x v2 = 3 x 14 + 80 two x v2 v2 = - 3 x 14 / 80 two = - 0.5 m/s The detrimental sign shows that he strikes in a course opposite to jacket , so as that the sum of his momentum and jacket's momentum is 0 As there is not any friction he will proceed to circulate without loss of velocity

Answer 4

You seem to be overlooking that the force of gravity acts upon all objects with mass, not just the earth.

Answer 5

Because the earth pulls the apple down, but the apple also causes the earth to be pulled "up", albeit a very very small amount.