Final answer:
In physics, an abrupt stop by a superhero catching someone just before they hit the ground would involve a fatal impulse due to the large force applied in a very short time. Falling on Jupiter would result in greater weight due to its stronger gravity. Skydivers reach terminal velocity where their acceleration decreases to zero.
Step-by-step explanation:
The question about comic book superheroes catching a person just before they hit the ground and why it would be as fatal as hitting the ground itself relates to the concept of impulse. Impulse is defined as the change in momentum experienced by an object, which is the product of the force applied to the object and the time period over which the force is applied. Shockingly, if a superhero catches a person at the very last second, the required force to stop the person's fall abruptly would have to be exceedingly large due to the very short time span available to stop the momentum (which is what would have been absorbed more gradually by a longer impact with the ground). Thus, the victim would still experience a potentially fatal force, similar to hitting the ground, which is why this rescue technique, despite its frequency in comics, is not realistic in terms of physics.
Moving onto the scenario of falling on Jupiter, the astronomer would fall faster on Jupiter due to its stronger gravitational pull compared to Earth. If we consider the weight of the astronomer in a capsule, with the floor of the capsule equipped with a scale, the scale would show her weight as significantly more compared to her weight on Earth. This is due to the higher gravitational force on Jupiter.
Skydivers reach a point known as terminal velocity, where the force of gravity is balanced by air resistance, leading to no further acceleration. At terminal velocity, the shape of the graph of the magnitude of the acceleration versus time for a falling skydiver flattens out as the acceleration approaches zero.