If the resultant of two forces of magnitude p and q are acting at a po...
Resultant of two compel given by
R=√(P2 + Q2 + 2PQ cosѳ)
R= √7Q
√7Q =√(P2 + Q2 + 2PQ cosѳ)
Squaring both sides
7 Q2 = P2 + Q2 + 2PQ cosѳ
Ѳ = 60
Cos 60 = 1/2
6 Q2 = P2 + PQ
Partitioned by Q2
6 = (P/Q)2 +P/Q
Let P/Q be x
x^2 +x – 6 = 0
x^2 + 3x-2x - 6 = 0
x(x+3)- 2(x+3) = 0
(x+3)(x-2) = 0
x =-3 ,x =2
P/Q =2
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If the resultant of two forces of magnitude p and q are acting at a po...
Given:
- Magnitude of force 1 (p) = p
- Magnitude of force 2 (q) = q
- Angle between the forces (θ) = 60 degrees
- Resultant of the forces (R) = √7q
To find:
- P/Q
Explanation:
1. Resolving Forces:
When two forces act at an angle, they can be resolved into two perpendicular components. Let's resolve the forces p and q into their respective components.
- Force p can be resolved into two components:
- p₁, which is parallel to the resultant force R
- p₂, which is perpendicular to the resultant force R
- Force q can also be resolved into two components:
- q₁, which is parallel to the resultant force R
- q₂, which is perpendicular to the resultant force R
2. Relation between Components:
The components parallel to the resultant force R add up, while the components perpendicular to the resultant force R cancel each other out.
Since the resultant of the forces is √7q, we can write the following equations:
- p₁ + q₁ = √7q (Equation 1)
- p₂ + q₂ = 0 (Equation 2)
3. Finding the Ratio:
To find the ratio P/Q, we need to express p and q in terms of their components.
From Equation 1, we can solve for p₁:
p₁ = √7q - q₁
From Equation 2, we can solve for p₂:
p₂ = -q₂
Now, we can substitute the values of p₁ and p₂ into the equation P/Q:
P/Q = (p₁ + p₂) / q
Substituting the values:
P/Q = (√7q - q₁ - q₂) / q
4. Simplifying the Ratio:
Since q₁ and q₂ are the components of force q perpendicular to the resultant R, we can relate them using trigonometry.
From the right-angled triangle formed by q, q₁, and q₂, we have:
sin(60) = q₁ / q
sin(60) = √3 / 2
q₁ = (√3 / 2) * q
Similarly, q₂ = (1 / 2) * q
Substituting the values of q₁ and q₂ into the P/Q equation:
P/Q = (√7q - (√3 / 2) * q - (1 / 2) * q) / q
P/Q = (√7 - (√3 / 2) - (1 / 2))
5. Final Ratio:
Simplifying the expression:
P/Q = (√7 - (√3 / 2) - (1 / 2))
P/Q = (√7 - √3 - 1) / 2
Hence, the ratio P/Q is (√7 - √3 - 1) / 2.
If the resultant of two forces of magnitude p and q are acting at a po...
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