 #1
tellas
A girl is climbing up a set of stairs and has her femur horizontal. Her thigh weighs 12 pounds, acting at a center of mass 15 cm from her hip joint. She places 50 pounds of weight on the lower portion of that leg, vertically through her knee. Her gluteus maximus is applying a force directed 30 degrees below the horizontal, at a point 8 cm from her hip joint. An unknown force is applied at her hip.
1. How much force is her gluteus maximus exerting on her femur?
2. WHat are the magnitude and direction of the unknown force applied to her hip?
3. Approximate her thigh as a thin rod, with a mass of 12 pounds. What is her thigh's moment of inertia about either end?
4. If she increases the force from her gluteus maximus to 500 pounds, with everything else being the same, what angular acceleration will her thigh experience about her hip?
I believe relevant equations would be:
angular acceleration= T/I
I=1/3Ml^2
For number 3 I tried to solve for moment of inertia by doing I= 1/3(5.4kg)(.4^2)
I am really confused on how I would solve the rest of the problems.
1. How much force is her gluteus maximus exerting on her femur?
2. WHat are the magnitude and direction of the unknown force applied to her hip?
3. Approximate her thigh as a thin rod, with a mass of 12 pounds. What is her thigh's moment of inertia about either end?
4. If she increases the force from her gluteus maximus to 500 pounds, with everything else being the same, what angular acceleration will her thigh experience about her hip?
I believe relevant equations would be:
angular acceleration= T/I
I=1/3Ml^2
For number 3 I tried to solve for moment of inertia by doing I= 1/3(5.4kg)(.4^2)
I am really confused on how I would solve the rest of the problems.
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