Great things are happening here. Notice that objects with air resistance reach incredibly high velocities as they fall into the upper atmosphere, where there is little air resistance. However, once it enters thick air, it slows down. Due to the low resolution of my atmospheric density model (at very high altitudes), the cockroaches exhibit strange speeds.
But all of these objects eventually reach some terminal velocity. For a bowling ball, this final velocity is 83 m/s (185 mph), but for a cockroach it is only 1.5 m/s (3.3 mph). The tennis ball is between these two and has a terminal velocity of 23.8 m/s (53 mph). If you want to try a different object, use the link to code and enter the value of the object you want to delete.
From a survivability perspective, cockroaches seem to have a chance of survival. If you’ve ever seen a cockroach, you know that they can easily move faster than a person can walk. Its speed is about 3 miles per hour. I feel like if I can move that fast on the floor, I can withstand impact with the ground at the same speed.
A tennis ball should be fine too. Its terminal velocity is that seen during a tennis match. But that bowling ball will probably break. If it hits a hard surface like cement or dry soil, it will definitely explode. Softer materials, such as water or mud, may be able to withstand the impact.
Falling and heating
If you’ve ever paid attention to anything related to space exploration, you know that objects become hot when they re-enter the atmosphere at very high speeds. The interaction between the object and the air creates an air resistance force that pushes backwards, but also compresses the air in front of the moving vehicle. This compressed air becomes hot and heats the front of the falling object. For a spacecraft during reentry, this heating can be very extreme, so extreme that a heat shield is required to prevent the rest of the spacecraft from melting.
So what about falling objects? Things can get pretty complicated, especially when you’re dealing with moving air at high speeds, and that’s okay. Since this is just a hobby and not a real aerospace application, a rough approximation can be used to calculate the amount of heating during the fall.