Question

A 3.10-mm-long, 430 kgkg steel beam extends horizontally from the point where it has been bolted to the framework of a new building under construction. A 69.0 kgkg construction worker stands at the far end of the beam.What is the magnitude of the gravitational torque about the point where the beam is bolted into place?

Answer 1

Answer:

Explanation:

Given that,

The length of the beam L = 3.10m

The mass of the steam beam $m_1$ = 430kg

The mass of worker $m_2$ = 69.0kg

The distance from  the fixed point to centre of gravity of beam = $\frac{L}{2}$

and our length of beam is 3.10m

so the distance from  the fixed point to centre of gravity of beam is

$\frac{3.10}{2}=1.55m$

Then the net torque is

$=-W_sL'-W_wL\\\\=-(W_sL'+W_wL)$

$W_s$ is the weight of steel rod

$=430\times9.8=4214N$

$W_w$ is the weight of the worker

$=69\times9.8\\\\=676.2N$

Torque can now be calculated

$-(4214\times1.55+676.2\times3.9)Nm\\\\-(6531.7+2637.18)Nm\\\\-(9168.88)Nm$

≅ 9169Nm

Therefore,the magnitude of the torque is 9169Nm