Question

(which statement is true)....As you sit in a chair at your computer, the chair exerts an upward supporting force n on you, and gravity exerts a downward force Fg on you. To a fairly good approximation, n =− Fg . Is this an example of Newton’s third law? 1.No;n+Fg ≈0 is due to the fact that your upward or downward acceleration happens to be almost negligible. 2.Yes; the “action” Fg must produce a “re-action” n . 3.Yes; your velocity happens to be zero. 4.Yes; the chair is attached to the earth, so both n and Fg are exerted by the earth.

Answer 1

I think there is what is known as a "normal" reaction which is enough to maintain equilibrium if the chair is strong enough. The computer is probably at rest, rather than in an elevator so the normal force will be equal to be weight - I say this because the normal force would be greater if the elevator was accelerating upwards (you might notice this as feeling heavier). This is an example of Newton's third law which is all about equal and opposite actions. Hope this helps, let me know if there's anything I haven't made clear.

Answer 2

N - mg = 0

N = mg

Answer 3

2.Yes; the “action” Fg must produce a “re-action” n

Answer 4

Just want to tell you that option 2 is wrong.. which option do you recommend from the rest of three??

Answer 5

I used option 2 but my teacher refused saying it is not right... so i am confused..

Answer 6

reply please..

Answer 7

I would ask your teacher to check if 2 actually is the correct answer to this question.

Answer 8

Ok... can I ask you one more question??