This isn't actually a real Iron Man suit. But it does fly. It's a flying suit made by Gravity Industries, a young British startup that builds what they call 'jet suits.' The system uses six kerosene-powered jet thrusters to let a human fly around. Honestly, it just looks cool.

This tweet states that it takes 1,000 horsepower to fly—how about an estimation to check this number?

The Physics of Flight

Let's start off with some fundamental physics. How does this jet suit fly? I'm going to say it's all about the momentum principle. This says that the net force on an object changes its momentum where momentum is the product of mass and velocity. Here is the equation form of this idea.

There is one other important idea about forces—they are an interaction between two objects such that for every force there is an equal and opposite force.

OK, now for flying. Suppose I have a human that is hovering above the ground. There is of course the gravitational force pulling down on the human so that there must also be an upward force to make the total force zero (so the human stays hovering). This upward force comes from the thrust of the micro jets. But how does a jet produce thrust? The answer comes from the momentum principle.