In the Fig above, MN is a light uniform meter rule pivoted at O, the 80cm mark. A load of mass 3.00kg is suspended on the meter rule at L, the 10cm mark. If the rule is kept in equilibrium by a string RP, fixed at P and attached to the rule at R, the 20cm mark, then the Tension T on the string is?
A
3.0N
B
3.4N
C
3.5N
D
6.0N
E
7.0N
Verified Correct Answer: E.
Physical Principles & Numerical Solution
T * sin30 \times 60 = 3 * 70
: T = 7N
Source: Official Exam / Past Question Archive