GR 8677927796770177 | # Login | Register

GR8677 #7
Problem
 GREPhysics.NET Official Solution Alternate Solutions

Mechanics$\Rightarrow$}Statics

Straight-forward Newtonian statics:

$F_x=0=F-T\sin(\theta)\Rightarrow T\sin(\theta)=F
$

$F_y=0=T\cos(\theta)-mg\Rightarrow T\cos(\theta)=mg
$

Divide the two equations above, cancel T's, and get: \par
$\tan(\theta)=\frac{F}{mg}=\frac{10}{2*10}=.5$. Choice A is right.

Alternate Solutions
 There are no Alternate Solutions for this problem. Be the first to post one!
ernest21
2019-08-10 03:09:43
The problem specifically says y and x are unitless, so does that thinking still hold? drumming games
joshuaprice153
2019-08-08 05:45:19
I simply stumbled upon your blog and desired to say that I possess really enjoyed browsing your current posts. keep doing your great job and always gain my support. cheers for sharing this beautiful article. commercial cleaning
casseverhart13
2019-07-09 07:03:22
You\'re really properly informed and extremely intelligent. Orlando Towing Partners Waterford Lakes
JasonHupp
2018-07-30 11:06:29
Seems like every one must remember the formulas to do the sum and get desired answer.\r\nhttp://www.pumpkin.com
pam d
2011-09-23 19:24:15
free points!
Dodobird
2010-11-04 18:15:41
Any solution must involve horizontal and vertical components of force.
Tangents satisfy this requirement.
Because the box weighs 2 kg already we see gravity, the vertical force, will be larger.
Opposite/Adjacent < 1 means that only A satisfies this requirement.
signminus
2010-08-01 12:15:58
Not quite. The question asks for the angle, $\theta$. As in the posted solution, we have
$\text{tan}(\theta)=0.5$.
To invert this equation, we do
$\text{tan}^{-1}(\text{tan}(\theta))=\text{tan}^{-1}(0.5)$
$\Longrightarrow \theta=\text{tan}^{-1}(0.5)$,
 signminus2010-08-01 12:16:42 Oops, meant that as a reply to rlorek's comment below.
rlorek
2010-07-30 12:32:55
This was worked out well, but the answers are looking for "arc" functions which are the inverse of normal trig functions.

The inverse of tan(theta)=0.5 is...

arctan(theta)=2.0

Therefor "C" should be the correct answer.
 flyboy6212010-11-09 20:27:00 If $tan \theta= .5$ then $\theta =arctan .5$ .
belle
2009-10-11 13:50:56
This also solvable with simple geometric tactics

tan(theta)=$\frac{10}{2g}$

using g=10

tan(theta)=.5

kostas
2007-01-09 12:42:27
I see the answers but I cannot find the questions. Where are they? There was a "jump into the question" buton in the old site that I can't see now
 yosun2007-02-22 19:09:03 I am in the process of typing up the questions. Currently, only GR8677 is available as graphics file displayed next to the official solution. GR9277 questions will be available shortly, and the rest, eventually.

LaTeX syntax supported through dollar sign wrappers $, ex.,$\alpha^2_0$produces $\alpha^2_0$. type this... to get...$\int_0^\infty$$\int_0^\infty$$\partial$$\partial$$\Rightarrow$$\Rightarrow$$\ddot{x},\dot{x}$$\ddot{x},\dot{x}$$\sqrt{z}$$\sqrt{z}$$\langle my \rangle$$\langle my \rangle$$\left( abacadabra \right)_{me}$$\left( abacadabra \right)_{me}$$\vec{E}$$\vec{E}$$\frac{a}{b}\$ $\frac{a}{b}$