2.2. B

Balanced نزاﻮﺘﻣ

In physics, balanced forces refer to a situation where all forces acting on an object are equal in size and opposite in direction, resulting in no change in motion. For instance, if two people push a box with equal strength from opposite sides, the box will remain in place because the forces cancel out. This balance is crucial in various fields, including engineering, where structures must withstand forces without collapsing.

Imagine you are at a playground and two friends are on a seesaw, both sitting equidistant from the center and weighing the same. Neither friend goes up or down because their weights are balanced. Just like the seesaw, structures need to be balanced with forces to maintain stability.

Bar ((cid:6454)ﺪﻌﻣ) ﺐ(cid:5980)ﻀﻗ

The term 'bar' in structural engineering often refers to rigid one-dimensional components that bear loads primarily through axial forces. These bars can be used in various constructions, such as bridges and buildings. They can handle tension (being pulled) or compression (being pushed). Understanding how these bars distribute forces is key to ensuring structural integrity.

Think of a simple clothesline made of a taut bar or rope. When you hang clothes on it, the bar is under tension from the weight of the clothes. Similarly, structural bars must support loads and be designed to resist the forces acting on them effectively.

Beam ةﺮﻤ(cid:5992) Beam cross section ةﺮﻤ(cid:6092)ﻠﻟ (cid:6461)(cid:6352) ﺮﻌﻟا ﻊﻄﻘﻤﻟا

Beams are horizontal structural elements that support loads and are vital in construction. They can come in various shapes and materials, and their cross-section can greatly affect their strength and how they distribute loads. For instance, an I-beam is widely used due to its high strength-to-weight ratio, which makes it efficient for supporting heavy loads.

Consider a well-balanced bridge made of beams. If you look closely, you can see that some areas are thicker or shaped like an 'I' to manage weight better. Just as a sturdy book spine supports the pages, beams support the structure overhead, making sure it doesn't collapse.

Cantilever beam ((cid:6473)ﻮﺑﺎ(cid:5992)) ةﺮﻤ(cid:5992)

A cantilever beam is a beam that is fixed at one end and free at the other. This structure is subject to bending moments due to the load applied. Engineers use cantilever beams in various applications, such as balconies or bridges, where only one end is supported. The design ensures that the structure can safely handle the weight and any forces acting upon it.

Picture a diving board at a swimming pool. It is attached at one end, while the other end is free to extend out over the water. When someone jumps on it, the supported end provides stability while the free end dips under the weight, showcasing the principles of cantilever structures.

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