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farshadian
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Hi I'm having trouble with my injury mechanics problem where a rigid window with frame falls from a verticle position on a person sitting below.
The decorative wood-framed window below has been inadvertently left
unrestrained in a nominally stable vertical position. The window pivots around its base until it strikes a person on the top of the head. Model the falling window to determine the velocity at head contact. then estimate the force applied to the head if the impulse is over 5 ms (assumed triangular contact).
Density of wood is 0.673 g/cc and glass is 2.6g/cc
DIMENSIONS are
2.0m wide frame
1.2 m high
15 cm thickness
Frame width is 20 cm everywhere and glass is in center.
a person is sitting 1.1m away from the center of the base (path of contact is
I know your supposed to use impulse and moment
and the parallel axis theorm. I can't figure out how to find the CoG for the block which is one of the first steps
cirumfrance of the falling obj. about the person is = pi * r /4 = 0.864 m
Area of whole thing is 2m*1.2m = 2.4 m2
Glass area is 0.8*1.6= 1.28 m2
area of the frame is 1.12m2 and its volume is 0.0064m3
volume of frame is .168 m3
mass of frame is .113 g and the window is .0166g
can anyone point me in the right direction?
Homework Statement
The decorative wood-framed window below has been inadvertently left
unrestrained in a nominally stable vertical position. The window pivots around its base until it strikes a person on the top of the head. Model the falling window to determine the velocity at head contact. then estimate the force applied to the head if the impulse is over 5 ms (assumed triangular contact).
Density of wood is 0.673 g/cc and glass is 2.6g/cc
DIMENSIONS are
2.0m wide frame
1.2 m high
15 cm thickness
Frame width is 20 cm everywhere and glass is in center.
a person is sitting 1.1m away from the center of the base (path of contact is
Homework Equations
I know your supposed to use impulse and moment
and the parallel axis theorm. I can't figure out how to find the CoG for the block which is one of the first steps
The Attempt at a Solution
cirumfrance of the falling obj. about the person is = pi * r /4 = 0.864 m
Area of whole thing is 2m*1.2m = 2.4 m2
Glass area is 0.8*1.6= 1.28 m2
area of the frame is 1.12m2 and its volume is 0.0064m3
volume of frame is .168 m3
mass of frame is .113 g and the window is .0166g
can anyone point me in the right direction?
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