Engineering Mechanics - Force Vectors - Discussion
Discussion Forum : Force Vectors - General Questions (Q.No. 1)
1.
The cord is attached between two walls. If it is 8 m long, determine the distance x to the point of attachment at B.
Discussion:
13 comments Page 2 of 2.
Mr. Right said:
1 decade ago
The answer is actually 7.68.
The diagram is not a right triangle, as it is in 3 dimensions and not on an x,y axis.
Correct approach:
A=0i+1j+4z.
B=?i+0j+2z.
Distance between 2 points in 3d:
sqrt((x2-x1)^2+(y2-y1)^2+(z2-z1)^2).
(x-0)^2 + (0-1)^2 + (2-4)^2.
x^2 + 1 + 4 = 8^2.
x^2=59.
x= sqrt59 = 7.68115.
Now if you check that you will see that it is correct, as opposed to the answer that you all tried to simplify and didn't bother to check your work.
The diagram is not a right triangle, as it is in 3 dimensions and not on an x,y axis.
Correct approach:
A=0i+1j+4z.
B=?i+0j+2z.
Distance between 2 points in 3d:
sqrt((x2-x1)^2+(y2-y1)^2+(z2-z1)^2).
(x-0)^2 + (0-1)^2 + (2-4)^2.
x^2 + 1 + 4 = 8^2.
x^2=59.
x= sqrt59 = 7.68115.
Now if you check that you will see that it is correct, as opposed to the answer that you all tried to simplify and didn't bother to check your work.
Jay aswani said:
1 decade ago
Sir please provide complete solution so that we can take advantage of that.
D.Vengadesan said:
1 decade ago
Sir I want explanation for this answer.
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