Final answer:
To determine the height from which Pochita fell, one must use the impulse-momentum theorem to calculate the initial velocity before impact and then apply conservation of energy principles to relate this velocity to the potential energy at the starting height.
Step-by-step explanation:
To find out from what height Pochita (a 15-kg object) fell, we first need to apply the impulse-momentum theorem, which relates the impulse exerted on an object to the change in momentum of the object. The impulse is given by the product of the average force exerted during the contact and the time interval of contact. Since Pochita comes to rest upon hitting the ground, her final velocity is 0, and therefore her change in momentum is equal to her initial momentum before hitting the ground, which is mass times velocity.
The initial momentum can be calculated by determining the velocity of Pochita just before the impact, which can be found by using the conservation of energy. The potential energy at the initial height will be equal to the kinetic energy just before impact. We can use the height (h) to calculate the potential energy (mgh), which will be equal to the kinetic energy (½ mv²).
The velocity just before impact can then be related to the impulse equation (Impulse = Change in Momentum). Given the average force and collision time, we can calculate the impulse, and using the mass of Pochita, we can calculate her velocity just before impact. Finally, we use this velocity to find out the height she fell from by equating kinetic energy and potential energy. The steps to solve this will involve a mix of kinematic equations and the understanding of forces in collisions.