Welcome Guest Search | Active Topics |

Tag as favorite
Torque
Options
Previous Topic Next Topic
spnixon
#1 Posted : Thursday, July 12, 2018 10:01:03 PM
Rank: Newbie

Groups: Registered
Joined: 6/5/2018
Posts: 0

Thanks: 0 times
Was thanked: 0 time(s) in 0 post(s)
For page 49 in the physics classroom companion, if we round 17 down to 16 and 0.24 to 0.25, isnt the denominator being estimated as lower than it really is, and so the actual number should be less than 625? Going by the answer in the back of the book, do we then assume that if we only round slightly, we are to pick the next closest number no matter if we rounded up or down?

Thank you
Back to top
Report?
robertmoscaritolo
#2 Posted : Monday, July 23, 2018 6:36:32 PM
Rank: Instructor

Groups:
Joined: 6/1/2013
Posts: 2

Thanks: 0 times
Was thanked: 0 time(s) in 0 post(s)
Hello,

The product on the right-side of the equation was 17 x F x 0.24. As you’ve stated, the solution rounded 17 down to 16 and 0.24 up to 0.25. The overall effect of this rounding produces 16 x F x 0.25 = 4F. The denominator is then indeed less than it actually is, which will cause the rounded answer to be a bit larger than it actually is. This would imply that the rounded answer of 625 N is larger than it actually is. So, everything you have said is correct. However, on the left side of the equation, 2700 was rounded down to 2500. Since we rounded the numerator down by a lot more than we rounded the denominator, this implies that the rounded answer will be less than it actually is. So, the rounded answer of 625 N serves as a lower limit, telling us that the actual answer should be larger than 625 N, which is why D is the best choice. Please let me know if you nee any further clarification.

Robert Moscaritolo
MCAT Physics Instructor, Prep101
Back to top
Report?
Users browsing this topic
Guest (2)
Tag as favorite
You cannot post new topics in this forum.
You cannot reply to topics in this forum.
You cannot delete your posts in this forum.
You cannot edit your posts in this forum.
You cannot create polls in this forum.
You cannot vote in polls in this forum.

Clean Slate theme by Jaben Cargman (Tiny Gecko)
Powered by YAF | YAF © 2003-2009, Yet Another Forum.NET
This page was generated in 0.069 seconds.