Final answer:
The terminal velocities of the skydivers can be calculated using the given formula and assumptions. The 60-kg skydiver will reach the ground in approximately 29.5 seconds, while the 90-kg skydiver will take approximately 45.6 seconds.
Step-by-step explanation:
In order to calculate the terminal velocities of the skydivers, we need to make some assumptions about their frontal areas. Let's assume that the frontal area of the 60-kg skydiver is 0.5 m² and the frontal area of the 90-kg skydiver is 0.6 m². The terminal velocity of an object falling in air depends on its weight and the area facing the fluid. It can be calculated using the formula:
Terminal Velocity = sqrt((2 * mass * g) / (density * frontal area * drag coefficient))
By plugging in the given values, we can calculate the terminal velocities of the skydivers. The 60-kg skydiver will have a terminal velocity of approximately 56.204 m/s, and the 90-kg skydiver will have a terminal velocity of approximately 53.122 m/s.
Assuming the time to reach terminal velocity is small, the 60-kg skydiver will take approximately 29.5 seconds to reach the ground, and the 90-kg skydiver will take approximately 45.6 seconds to reach the ground.