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Consider the following statements, regarding a girl who wants to jump vertically upward from a hard horizontal floor. Symbolic representation of forces is given below. vec(F)_(M) = force developed in leg muscles, vec(F)_(W) = Weight, vec(F)_(N) = Normal reaction |
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Answer» Total force on FLOOR is `vec(F)_(M)+vec(f)_(w)`. When the girl is bending her LEGS, the total force exerted by her legs in the action, normal force by grand is the reaction. Considering FBD of girl `vec(F)_(N)+vec(F)_(w)=mvec(a)` `vec(F)_(N)=-vec(F)_(M)` So force on floor is `vec(F)_(M)` Resultant force on giel is `vec(F)_(w)-vec(F)_(M)` NOTE: If we say the change in force of girl is `vec(F)_(M)`, then (A) and (B) WOULD also be correct. |
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