Blown over

I went outside for lunch and was almost blown over by the wind. I really had to struggle through the air to get to the pedestrian crossing. I think, in fact, I leaned forward at an angle that would normally result in me falling on my face, but the wind held me up.

As only a nerd would, as I battled against the forces of nature, I thought how this could be represented as a free body diagram.

This doesn’t seem right to me. I feel like Fwind was actually horizontal and that a component of my weight force was horizontal in the other direction. Can that be right? For this diagram, I’ve drawn that the horizontal wind force is opposed by the ground reaction force (GRF). I am almost sure this is wrong because the GRF should actually be opposing the force of the foot on the ground.

I did lots of web searching to find a free body diagram of something toppling over and I couldn’t find it. Is it something to do with torque around the centre of gravity?

Sigh. I really should know how to do this. I’m an engineer.

Any help would be appreciated!


  1. Yap! It's 3088.. says:

    i am just as nerd. I tried to understand why people keep knocking onto me whenever i jog pass them even though they were walking in a straight line. they’ll unconsciously swerve to my side as i approach them from behind. i think the toppling effect in your case can be solved with torque, as you have mentioned.

  2. Daniel says:

    yeah, it totally revolves around the torque thing…

    you need to consider where the center of your aerodynamic cross-section is (there’s probably a proper technical term for that) in relation to your center of mass and the point of contact on the ground. I have to think about this sort of stuff all the time when I’m skating…

Leave a Reply

Your email address will not be published. Required fields are marked *