Helicopter Physics: From the Mars Helicopter to the Human Powered Helicopter

It’s the end of the introductory physics course. That means that the students have seen some of the very fundamental ideas in physics such as:

• The momentum principle.
• The work-energy principle.

Really, that’s all you need to explore some really cool physics. In this case, it’s time to use these ideas to build a model of helicopter thrust and power. With that, we can look at some awesome helicopter examples. Let’s get started.

Hovering Helicopters

Suppose you have a helicopter hovering such that it has a zero acceleration. Since the acceleration is zero, the total force on the helicopter must also be zero.

Looking at just the forces in the y-direction (the vertical direction), this would be:

This means that there must be some force (due to the interaction with the air) that pushes up on the helicopter. Also, the magnitude of this force must be equal to the gravitational weight of the aircraft (on Earth, g = 9.8 N/kg).

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Physics faculty, science blogger of all things geek. Technical Consultant for CBS MacGyver and MythBusters. WIRED blogger.