sample post DO NOT COPY How to rescue a falling person A sample blog post based

sample post DO NOT COPY How to rescue a falling person A sample blog post based on a movie clip *First I introduce what I found in the world that relates to forces* I would like to talk about a scene from the movie A Wrinkle in Time. In the scene a small child falls from a great height and is rescued by a field of sentient flowers. I assume most people have not seen the movie, and while I don’t have the actual scene of the rescue, you can see the flowers themselves being introduced in this clip. At the very end of the clip you also see the creature the kids eventually ride on from which the small boy falls. The narration by the director is fascinating, but not at all related to physics. Watch VideoLinks to an external site. *Next step is to identify the interaction* What is remarkable in the rescue scene is that the flowers fly up into the air to meet the child and then very gradually slow him down until he comes to a gentle rest on the ground. The relevant interaction is between the flowers and the boy. *Next I identify relevant class concepts* There are a couple components of the Force Model of Interactions that are relevant to rescuing a falling person. From our studying of falling objects we know that a falling object will speed up while falling until it reaches terminal velocity. We also know that Force depends on the rate of change of speed. If there is a big change of speed over a very short amount of time, the force applied must be very big. If the force is small, the rate of change of speed must be small. We also learn that when multiple forces are acting on an object, the net force takes all the acting forces into account. We also know that the forces two objects exert on each other are equal and opposite. *I then connect the dots by explaining how the concepts mentioned apply to this situation.* The flowers that save the young boy understand physics. If the flowers did the Superman version of a rescue, they would catch him right at the bottom of his fall and whisk him up, up and away. The bottom of the fall is when he would be traveling the fastest. The force needed to very quickly reduce his speed to zero and then speed him up in the opposite direction (upward), would be HUGE. Human bodies do not respond well to such huge forces – bones break, organs splat, it’s not pretty despite how easy the movies make it. Instead the flowers fly up to meet the boy as he’s falling. This means that his speed is not as great as it will eventually be, which means not as much force will be needed to slow him down. Also, they have bought themselves time. There are still many seconds before the boy would hit the ground without being slowed, and as they slow him, there is even more time. Compared to Superman, the flowers need to supply a smaller change in speed over a much longer time. Smaller change in speed over a longer time means the rate of change of speed is quite small. Since the force is proportional to the rate of change of speed, the force the flowers need to produce is likewise, small. The boy can withstand a small force over a long time without breaking a single bone or liquifying a single organ. Since gravity is acting, the upward force produced by the flowers must be bigger than gravity, but it doesn’t have to be much bigger. The net force will be a very small upward force. *Finally, I conclude, tying everything back to the original observation.* Those are definitely some smart flowers, slowly changing a person’s speed to make sure they are truly rescued. PS The flowers aren’t the only time it is evident that they consulted with physicists in the making of the film. It is very physics friendly.