Mastering Physics: HMwk #5 x C we will Look At An E M My Questions l Yahoo Ansa
ID: 1331316 • Letter: M
Question
Mastering Physics: HMwk #5 x C we will Look At An E M My Questions l Yahoo Ansa x G free body diagram tension... x t c tion pair between the two boxes 1h e E https /myct 54773345 masteringphysics.com Session Physics 2001 Fall 2015 Signed in as alexys barsy l Help Close Resources a HMWK #5 Problem 5.10 previous l 14 of 20 l next Problem 5.10 Part A A heavy mirror that has a width of 2 m is to be hung on a What is the shortest length of wire L that can be used to hang the mirror without the wire breaking? (lgnore any friction forces between the wall as shown in the figure below mirror and the wa Express your answer in meters to three significant figures. Submit My Answers Give U 1 incorrect; Try Again The mirror weighs 700 and the wire used to hang it will break if the tension exceeds 700 N (breaking Provide Feedback Continue strength)Explanation / Answer
Let angle made by string with mirror is A
Tension T acts along strings on both sides
vertical component of tension in strings balance weight of mirror
T sinA + T sinA = Weight of mirror
2T sinA = 700
Maximum tension = 700 N
2(700) sin A = 700
A = 30 degrees
cos A = Adjacent/Hypotenuse
cos 30 = 0.5 m/ (L/2) [ In diagram width of mirror = 1m, so half the width =0.5 m]
L = 1.154 m
cos 30 = 1 m/ (L/2) [ In question width of mirror = 2m, so half the width =1 m]
L = 2.309 m