When a person jumps from a tree to the ground, what happens to the momentum of the person upon striking the ground?

According to the law of conservation of linear momentum, if no external force acts on the system, the momentum of a system remains conserved.

For example, consider a system of two objects which collide head-on. If no external force acts on the system, the total momentum of the system before collision will be equal to the total momentum after the collision.

When a person jumps from the tree to the ground, it strikes the ground. Consider the collision of person on the ground (earth). The momentum of a person keeps on changing during the jump. The velocity of the person will become zero on striking the ground. Therefore, the momentum of the person will become zero.

The momentum of the person will get transferred to the ground. Since the earth is a massive object, its velocity will be very low, which cannot be noted.