Final answer:
The momentum of the flier just after launch is approximately 668.48 kg*m/s.
Step-by-step explanation:
To find the momentum of the flier just after launch, we can use the principle of conservation of momentum. Before the launch, the total momentum of the three people falling onto the airbag is zero, since they are all initially at rest. After the launch, the total momentum of the system is still zero, since no external forces act on the system. This means that the momentum gained by the flier is equal in magnitude but opposite in direction to the momentum lost by the three people falling onto the airbag.
Since all four people have the same mass, the momentum of the flier just after launch is equal in magnitude to the momentum lost by each person falling onto the airbag. We can use the equation for momentum, which is given by:
momentum = mass * velocity
Given that the three people fall a height of 8.5 m and the flier is launched vertically 16 m into the air, we can calculate the velocities at impact and launch respectively using the equation:
(1/2) * mass * velocity2 = mass * gravity * height
Substituting the values, we find that the velocity at impact is approximately 10.22 m/s and the velocity at launch is approximately 9.02 m/s. Therefore, the momentum of the flier just after launch is approximately 74 kg * 9.02 m/s = 668.48 kg*m/s.