Mastering Physics: Homework 7 Google Chrome https:// mastering physics.com /myct
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Mastering Physics: Homework 7 Google Chrome https:// mastering physics.com /myct/itemView assignment ProblemID 56014817 ession Physics 1250 Engineering Physics I Fall 2015 Homework 7 Problem 6.71 Problem 6.71 Part A A small block with a mass of 0.0600 kg is attached to a cord passing What is the tension in the cord in the original situation when the block has speed vo 0.61 m/s through a hole in a frictionless, horizontal surface (Figure 1). The block Express your answer with the appropriate units. is originally revolving at a distance of 0.43 m from the hole with a speed of 0.61 m/s. The cord is then pulled from below, shortening the radius of the circle in which the block revolves to 0.17 m. At this new distance, the speed of the block is 1.54 m/s Units Subm My Answers Give Up Part B What is the tension in the cord in the final situation when the block has speed vi 1.54 m/s Express your answer with the appropriate units. Figure 1 Units Subm My Answers Give Up Part C How much work was done by the person who pulled on the cord? Express your answer with the appropriate units. W Value Units Signed in as Walaa Aljefri l Help l Close Resources previous l 5 of 12 l next 8:22 PM NG 0/28/20Explanation / Answer
here,
mass , m = 0.06 kg
d1 = 0.43 m
v1 = 0.61 m/s
d2 = 0.17 m
v2 = 1.54 m/s
(a)
the tension in the cord in the original situation , To = m*v1^2/d1
To = 0.06 * 0.61^2 /0.43
To = 0.052 N
the tension in the cord in the original situation is 0.052 N
(b)
the tension in the cord in the finalsituation , Tf = m*v2^2/d2
To = 0.06 * 1.54^2 /0.17
To = 0.84 N
the tension in the cord in the original situation is 0.84 N
(c)
the work done , W = KEf - KEi
W = 0.5 * m * ( v2^2 - v1^2)
W = 0.5 * 0.06 * ( 1.54^2 - 0.61^2)
W = 0.06 J
the work done by the person who pulled the rope is 0.06 J