Everybody has same comment about Batman: He’s cool because he’s just a normal guy, but he’s also a superhero. It’s true, he doesn’t have superpowers. But what he do gardening is a combination of skills and equipment.
In the movie Batman, we get to see him use one of his “toys” – his ascender gun. (It’s also known as a grappling gun or a grappling gun.) Batman uses it to fire something like a grappling hook, which is connected to a cable. Once attached to a high point, an electric motor in the gun pulls the cable and pulls Batman up.
In this scene, Batman is in a building with a group of Gotham police officers who have detained him. He doesn’t think it’s such a good idea. After breaking free, he runs to an interior stairwell and shoots the cable up near the top of the stairwell, then activates the motor to pull him up. Spoiler: He escapes. (But you probably knew that.)
Now for the physics calculations: What kind of battery or power source would his ascender need and how much power would it use? Let’s start with some background on energy.
Energy for the ascent
One of the key ideas for understanding energy is to define a system of interest, which is the collection of objects we want to study. (Of course, the most complete system is the entire universe, but it is not very practical to deal with it all at once. Instead, we want to isolate only the objects in which we are interested.)
Let’s use the following system: Batman plus the ascender (and its battery) and Earth. (You might think Earth is an odd thing to add to the system, but hang in there. We’ll get there.)
Once we have a system, we can use one of the most important concepts in physics: the work-energy principle. This says that the work done on a system is equal to the change in the energy of the system. But what the heck is energy?
It’s actually a tough question, but here’s my best answer: Energy is not a real thing, but rather a way of keeping track of various interactions. Energy also comes in different forms. For example, kinetic energy is associated with the motion of objects, and potential energy is the kind that depends on the position of objects.
So work is a way of adding or removing energy from a system. In terms of forces, we define work as the following:
Illustration: Rhett Allain