Need Help Magnitude and Forces problem

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The discussion centers around a biomechanics problem involving a runner navigating a turn on a track, requiring calculations of lean angle, force distances, and moments about the mass center. The user expresses confusion about how to approach the problem, indicating a lack of background in biomechanics despite being in a graduate program. Key concepts mentioned include the radial force formula (MV²/R) and the need to balance centripetal force through weight shifting. Participants suggest drawing diagrams to visualize forces and applying relevant equations to solve the problem. The conversation emphasizes the importance of understanding the physical principles involved in the scenario.
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Need Help ASAP! Magnitude and Forces problem

Homework Statement




Based on a free body diagram of a runner running around a turn on a track:

1. An estimate of the lean you would have while running at your maximum speed on a university track and
2. estimates of the relative distances between your mass center and the various forces depicted in the free body diagram, and
3. an estimate of the magnitudes of the forces depicted in the free body diagrams,

You should:
Calculate the magnitudes and directions of the moments produced about the mass center by each of the forces shown in the free body diagram. The moment magnitudes should be given with appropriate units or dimensions.

Weight is 150lbs or 68kg
Height is 5'8
 
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sfs007 said:

Homework Statement

Based on a free body diagram of a runner running around a turn on a track:

1. An estimate of the lean you would have while running at your maximum speed on a university track and
2. estimates of the relative distances between your mass center and the various forces depicted in the free body diagram, and
3. an estimate of the magnitudes of the forces depicted in the free body diagrams,

You should:
Calculate the magnitudes and directions of the moments produced about the mass center by each of the forces shown in the free body diagram. The moment magnitudes should be given with appropriate units or dimensions.

Weight is 150lbs or 68kg
Height is 5'8

Welcome to PF.

What would be your attempt at a solution?
 


I don't know where to start. I am in grad school for Health promotion and this is a biomechanics class which I know nothing about
 


sfs007 said:
I don't know where to start. I am in grad school for Health promotion and this is a biomechanics class which I know nothing about

What is the radius of the track?

When you are traveling around a curve what is the radial force? MV2R.
http://hyperphysics.phy-astr.gsu.edu/hbase/cf.html#cf

What weight shift do you need to compensate for that? That would be the centrepital force you need to balance. You balance that with your weight shifted how far? Draw a diagram and figure how to balance with the foot as a pivot. Weight down times shift must be Centripetal force times the height of the Center of mass away from the foot.
 


still lost me!
 


sfs007 said:
still lost me!

Sorry, I can't do the problem for you.

Look at the equations.

Make a drawing of the forces involved, the runner overhead to figure the mv2/R and then head on and identify the side force you just calculated and how shifting the weight from over the center of mass can offset it.
 
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