Under equilibrium, net torque is zero:

$\overline{){\mathbf{\Sigma}}{\mathbf{\tau}}{\mathbf{=}}{\mathbf{0}}}$

Similarly, the net force is zero:

$\overline{){\mathbf{\Sigma F}}{\mathbf{=}}{\mathbf{0}}}$

**Part A**

The net torque about the legs of the woman is zero.

Therefore:

$\begin{array}{lcl}\mathbf{\Sigma}\mathbf{\tau}& \mathbf{=}& \mathbf{w}\mathbf{(}\mathbf{54}\mathbf{\times}{\mathbf{10}}^{\mathbf{-}\mathbf{2}}\mathbf{)}\mathbf{-}{\mathbf{F}}_{\mathbf{N}}\mathbf{(}\mathbf{76}\mathbf{\times}{\mathbf{10}}^{\mathbf{-}\mathbf{2}}\mathbf{)}\mathbf{=}\mathbf{0}\\ {\mathbf{F}}_{\mathbf{N}}\mathbf{(}\mathbf{76}\mathbf{\times}{\mathbf{10}}^{\mathbf{-}\mathbf{2}}\mathbf{)}& \mathbf{=}& \mathbf{w}\mathbf{(}\mathbf{54}\mathbf{\times}{\mathbf{10}}^{\mathbf{-}\mathbf{2}}\mathbf{)}\\ {\mathbf{F}}_{\mathbf{N}}& \mathbf{=}& \frac{\mathbf{\left(}\mathbf{670}\mathbf{\right)}\mathbf{(}\mathbf{54}\mathbf{\times}{\mathbf{10}}^{\mathbf{-}\mathbf{2}}\mathbf{)}}{\mathbf{(}\mathbf{76}\mathbf{\times}{\mathbf{10}}^{\mathbf{-}\mathbf{2}}\mathbf{)}}\end{array}$

A woman weighing 670 N does a pushup from her knees, as shown in the figure. (Figure 1)

Part A What are the normal forces of the floor on each of her hands? Express your answer to two significant figures and include the appropriate units.

Part B What are the normal forces of the floor on each of her knees? Express your answer to two significant figures and include the appropriate units.

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