Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Calculating force of impact and maximum moment

  1. May 1, 2012 #1
    We have the following problem we're trying to solve:

    A helicopter is landing at 6 ft/sec, with its nose tilted up 15 degrees. We're designing a bumper that sits under the tail that has to absorb enough energy to reduce the maximum moment experienced by the tail to 350,000 in. lbs. Our bumper is sitting 338 inches behind the helicopter's center of gravity.

    To absorb the energy, we have a crushable aluminum material that is a cylinder 7 inches long, with radius 3.25 in. We need to pick the exact material by finding the pressure (in psi) that the material should crush at.

    We started by finding the initial KE of the helicopter, which is 1/2mv^2=1/2(26,500lb)(72 in/sec)^2 = 68,688,000 lb in^2. There must be a way to use the maximum moment to find out how much energy our bumper needs to absorb, and from there since W=Fxd, F=W/d=W/7 in. What are we missing here?

    Thanks
     
  2. jcsd
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted



Similar Discussions: Calculating force of impact and maximum moment
Loading...