Spider-Man is a favorite of mine. It's not because I like the Tom Holland version. Andrew Garfields and Toby McGuires versions are not the reason. I owe it all to the comic books I read as a teenager. Since childhood, I have been a Spider-Man enthusiast.
With great fandom comes great responsibility for analyzing trailers. Let me take a look at the latest trailer for Spider-Man: The Way Home. It is out December 17. It begins right where the last movie ended: Spider-Man riding through the city with his girlfriend, MJ.
I would like to calculate the force required by MJ to hold onto Spidey during one these swings, using only her arms. This will require some calculations based on video analysis and basic physics concepts. Let's get started.
Hanging on a Stationary Website
Let's begin with the forces that are affecting MJ. Let's say she is stationary and Spider-Man is hanging from a web. Let's say Spider-Man doesn't help her stay up. He might be busy with web-building or some other activity. It's as though she's holding on to Spider-Man. That's easier to draw. Below is a diagram of the forces that are acting on her.
Illustration: Rhett Allain
There are only two forces you need to be aware of. The first is the downward-pulling gravitational forces (labeled mg). This is actually an interaction of her mass (m), and the Earth's mass (m). The Earth part of the interaction can be represented by the gravitational field, which has a value around 9.8 newtons/kilogram.
The web's second force is the upward-pulling force. This force is often called tension, and the symbol T is used.
But what about the arrows? This simply means that both forces can be considered vectors. Vectors are quantities that have direction.
We are familiar with the net force that an object exerts on it and its motion. This is also called acceleration (a). This second law is Newton's. It looks like this:
