Simple physics question

College Search & Selection
1

<p>It seems none of my friends can figure this question out; but it seems simple.</p>

<p>A woman who weighs 600 N sits on a chair with her feet on the floor and her arms resting on the chair's armrests. The chair weighs 95 N. Each armrest exerts an upward force of 25 N on her arms. The seat of the chair exerts an upward force of 520 N. </p>

<p>What is the sum of the external forces?
A) 600 N
B) 1100 N
C) 500 N
D) 0 N
E) 100 N</p>

<p>I thought about this problem but it seems that the answer should be 695 N.. thoughts?</p>

2

<p>Damn, the answer is E)</p>

<ul>
<li>denotes positive z-direction</li>
</ul>

<p>Vector SUM = -600-95 +(25x2)+520 = -125 …. Rounded as 100 Newton!!!</p>

3

<p>Nope lol I have one chance left now. I got the other 2 questions for this problem but this last one is bugging me. So if anyone has another answer please make sure you're right b/c this is my last chance lol. THanks</p>

4

<p>Umm, considering the chair is bolted down to the ground:</p>

<p>I would say the fat lady’s not gonna feel any force, the answer is 0</p>

<p>695-590 >0</p>

5

<p>Hey thanks a lot it's right!</p>

6

<p>Glad to be of help :rolleyes:</p>

7

<p>seems like since the chair's not moving, the sum of the forces must be zero.</p>

8

<p>Well it makes sense but I was thinking external forces meant how much the ground was pushing up on the chair and the woman, but I guess I forgot the gravitational force?</p>