- #1
wetcarpet
- 10
- 0
There are two wires connected to a ceiling with a light fixture hanging at their ends. The light fixture exerts a force of 80N, while the wires make a 40 degree angle with the ceiling. What is the tension in the two strings? The diagram roughly looks like this:
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80N
I assumed that this was a simple trigonometry problem and set about solving it like so:
{a} I assumed that since the object was not moving downward, there had to be an 80N force exterted upward. Hence, I split the large triangle into two parts using a positive 80N force, making a 90 degree angle with the ceiling, and a 50 degree angle at the base of the larger triangle.
{b} From there I used trigonometry:
cos(50) = 80N/Hyp.
Hyp. = 80N/cos(50)
Hyp. = 124.5N
Yet, the software (Webassign.com) is telling me that the tension is not 124.5N. What am I doing wrong?
P.S.- I also tried assuming that there is not an 80N positive force exerted upward, and thereby tried isolating each X and Y vector for each string seperately. I still got the same answer of 124.5N.
---------------
- 40 40 -
- -
- -
-
-
80N
I assumed that this was a simple trigonometry problem and set about solving it like so:
{a} I assumed that since the object was not moving downward, there had to be an 80N force exterted upward. Hence, I split the large triangle into two parts using a positive 80N force, making a 90 degree angle with the ceiling, and a 50 degree angle at the base of the larger triangle.
{b} From there I used trigonometry:
cos(50) = 80N/Hyp.
Hyp. = 80N/cos(50)
Hyp. = 124.5N
Yet, the software (Webassign.com) is telling me that the tension is not 124.5N. What am I doing wrong?
P.S.- I also tried assuming that there is not an 80N positive force exerted upward, and thereby tried isolating each X and Y vector for each string seperately. I still got the same answer of 124.5N.