Question 20In figure below, a uniform bar of length l m is supported at its ends and loaded by a weight W kgf at its middle. In equilibrium, find the reactions R1 and R2 at the ends.[Hint : In equilibrium R1 + R2 = W and R1×l2=R2×l2R_{1} imes\dfrac{l}{2} = R_{2} imes\dfrac{l}{2}R1×2l=R2×2l]

Question

Question 20In figure below, a uniform bar of length l m is supported at its ends and loaded by a weight W kgf at its middle. In equilibrium, find the reactions R1 and R2 at the ends.[Hint : In equilibrium R1 + R2 = W and R1×l2=R2×l2R_{1}	imes\dfrac{l}{2} = R_{2}	imes\dfrac{l}{2}R1​×2l​=R2​×2l​]

Accepted Answer

As we know, the principle of moments states that

Anticlockwise moment = Clockwise moment

R₁ + R₂ = W

Given, the system is in equilibrium so

$R_{1}\times\dfrac{l}{2} = R_{2}\times\dfrac{l}{2}$

Since, R₁ = R₂ and 2R₁ = W

Therefore, R₁ = W/2 = R₂

Force — Question 20

Question 20