3 kg of wet clothes are hung on the middle of a clothesline with posts...
- If the clothes are hung in the middle of the line, this means we can treat the horizontal portion of a triangle as 3ft, and with the line sagging down 3ft, we can treat this as a 45-45-90 triangle, since the vertical and horizontal sides are equal.
- If the weight of the clothes pulls the line into the equivalent of a 45-45-90 triangle triangle, we can treat the force vectors accordingly.
- Because there are two anchor points for the clothesline, we can assume the horizontal components cancel each other out. The vertical component, 30N (F=ma, using 10m/s2 for the gravitational constant) should then equal Tcos45 + Tcos45, or 2Tcos45 since we have a 45-45-90 triangle. (sin45 could also be used, remember that cos45 = sin45)
- Solve for T:
2∗T∗cos 45 = 30
T∗cos 45 = 15
T∗(1/√(2) T = 15
T = 15√(2)
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3 kg of wet clothes are hung on the middle of a clothesline with posts...
Given data:
- Weight of wet clothes: 3 kg
- Distance between posts: 6 ft
- Sag in the clothesline: 3 ft
Calculating the tension:
- The weight of the clothes creates a vertical force downward.
- The tension in the clothesline creates a force upward.
- The sag in the clothesline creates a horizontal force component.
Vertical forces:
- The weight of the clothes creates a force of 3 kg * 9.8 m/s^2 = 29.4 N downward.
- The tension in the clothesline must balance this force, so the tension is also 29.4 N upward.
Horizontal forces:
- The sag in the clothesline creates a horizontal force component that must also be balanced by the tension in the clothesline.
- The sag is 3 ft, so the horizontal force component is 3 ft * 9.8 m/s^2 = 29.4 N.
- The total horizontal force is 2 * 29.4 N = 58.8 N.
Calculating the total tension:
- The total tension in the clothesline is found by combining the vertical and horizontal components.
- Using Pythagoras' theorem, T^2 = 29.4^2 + 58.8^2 = 3061.2.
- T = sqrt(3061.2) = 55.31 N.
- The total tension upon the clothesline is 55.31 N, which is approximately 15√2 N.
Therefore, the correct answer is option A) 15√2 N.