fig 10 shows a see-saw which is perfectly in balance, the weighs of the people sitting on it are 50kg, xkg and 15kg as shown, the sit at distances of 1.5, 1.5 and 2m from the pivot respectively. The vale of X is
Attached Figure / Diagram
A
30
B
35
C
70
D
24.25
E
impossible to find
Verified Correct Answer: A.
Physical Principles & Numerical Solution
Taking a moment about the pivot,
(15 x 2) + (x X 1.5) = 50 x 1.5
30 + 1.5x = 75
1.5x = 75 - 30 = 45
x = \(\frac{45}{1.5}\) = 30kg
Source: WAEC / JAMB / NECO Classroom Archive (Record #41604)