Here there is a group of people jumping into the air at different times. If they did not use their own force to jump, each of them would all stay at rest according to Newton’s first law called inertia, which states that an object at rest will stay at rest unless a force is acted upon it and an object in motion will stay in motion unless a force is acted upon it. Therefore, everyone who jumped would keep going upward but there are multiple forces, like the force of gravity, that pull them back down. Also, the amount of mass each person also is a also a force that stops them from continuously going upward. If a person has more mass, they will come down more quickly where as a person with less mass will take longer to come down.