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Homework Help: How far could I kick a bus if I were a Mantis Shrimp?

  1. Jan 23, 2008 #1
    How far could I kick a bus if I were a Mantis Shrimp?


    Hello. Strange title I know, but I am trying to come up with an analogy to demonstrate the force generated by the strike of a Mantis Shrimp's claw to explain it to a group of ten year olds. In theory, how far could a human of say 65kg kick an 8 tonne Double-decker bus, both vertically and/or horizontally? I do not need an absolutely accurate result, just an appoximation.

    Force generated at point of strike is a whopping 10 400 g

    Weight of double decker bus = 8000kg

    Speed of strike is 23m/s/s

    Do I need any other stats? please let me know.

    If anyone could help I would be very grateful.
    Although an enthusiastic amateur, I am no physicist, just a humble artist.
    Last edited: Jan 23, 2008
  2. jcsd
  3. Jan 23, 2008 #2
    ITS good to see ya ..be enthusiastic but this ques is pretty simple...


    force = 10.4 kg

    wt= mass*g
    >>mass=wt/g>>8000/9.8=816.32 kg

    now force = mass*accln

  4. Jan 23, 2008 #3
    Thanks Physixguru for your prompt reply, although I think I may have misled with my notation :
    the g-force is 10 400 g

    So, just one more q: now I have the acceleration rate, how do I work out the actual distance? Or am I just being dim...

    if s= ut + 1/2 at^2

    I have the initial velocity (0)
    but not the time t (although the time of a Mantis Shrimps 'kick' would be less than 1 second) or the final velocity v can I still work it out?

    Thanks for your patience
    Last edited: Jan 23, 2008
  5. Jan 24, 2008 #4
    u can still work it out using the general kinematics equations...
    but if speed of kick is wat u want to emphasise on ..then...impulse factor would come into play...
  6. Jan 24, 2008 #5


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    Once the bus leaves the leg of the enlarged shrimp it will follow a parabolic path. The maximum range will be achieved it is kicked at an angle of fourty five degrees upwards. The range it will then achieve depends on its velocity as it leaves the foot of the shrimp. Now the kick executed by the foot of the shrimp accelerates the bus during the kick. This means that the speed of the bus will increase during the kick. What one therefore need to know is the duration or the distance of the kick in order to determine the launching speed of the bus as it leaves the foot of the shrimp.
    Last edited: Jan 24, 2008
  7. Apr 1, 2008 #6
    So Long & Thanks For All The Shrimp

    Thanks to every one who replied to my query - and sorry that I haven't replied earlier.
    As part of a small design team I had to come up with an educational interactive demonstration of the power of a mantis shrimp.
    Thanks to you all, we've been able to work out an analogous model of the shrimp & the double-decker bus, and it's being built at the moment - ready for public display in the summer.

    I have recommended Physics Forum to many friends and colleagues, and I hope to pick your brains again soon ( not in a cannibalistic way )
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