Read the text about a person in motion. Valentina performs stunts on movie sets. For one stunt, Valentina started on the first story of a building. She ran up a staircase until she reached the third story. She dashed to a balcony, where she slid down a rope into an open window on the second story of another building. She landed safely on the floor inside the open window. When was the least gravitational potential energy stored between Valentina and Earth? Assume that Valentina's mass did not change. when she was at the bottom of the staircase when she was standing on the balcony when she was on the floor inside the window

To determine when Valentina had the least gravitational potential energy stored between her and the Earth, we need to understand the concept of gravitational potential energy (GPE). The gravitational potential energy of an object is given by the formula: \[ GPE = mgh \] where: - \( m \) is the mass of the object, - \( g \) is the acceleration due to gravity (approximately \( 9.81 \, \text{m/s}^2 \)), - \( h \) is the height of the object above a reference point (in this case, the ground). Now, let's analyze the three positions mentioned in the problem: 1. **At the bottom of the staircase**: This is the lowest point in Valentina's motion, so her height \( h \) is at its minimum. Therefore, her gravitational potential energy is also at its minimum. 2. **Standing on the balcony**: At this point, Valentina is higher than at the bottom of the staircase, so her height \( h \) is greater, resulting in a higher gravitational potential energy. 3. **On the floor inside the window**: This position is also above the bottom of the staircase, so her height \( h \) is greater than at the bottom, leading to a higher gravitational potential energy compared to when she was at the bottom. From this analysis, we can conclude that the least gravitational potential energy stored between Valentina and the Earth occurs when she was at the bottom of the staircase. Thus, the answer is: **When she was at the bottom of the staircase.**