Ielts Academic Writing Task 1 The diagram below shows how a mechanical arm works

 

The diagram below shows how a mechanical arm works, and how the joints that make up the arm function in the same way as those in a human arm. Summarize the information by selecting and reporting the main features, and make comparisons where relevant

 

The given diagram elucidates how a robotic arm works in a similar fashion to a human arm while performing tasks such as spray painting, drilling and welding. 

Overall, a mechanical arm is controlled by three computer monitored  motors and has joints similar to a human arm.  

 This arm is anchored to the foundation at the shoulder. This base is usually not moving, but sometimes it is movable. The movement of raising or lowering the arm is supported by the pivot installed between the shoulder and the base. This part also allows rotation of the whole arm, allowing it to work just like a human shoulder. 

The elbow in the middle allows free movement including flexing and rotating, affording complete flexibility to the whole equipment. Similarly,   the wrist of the mechanical arm functions just like a human counterpart allowing hand free movement, gripper  in this case. Gripper is equipped  with sensors to control force of hold. Gripper can be replaced by other end-effectors:  spray paint, drilling and welding metals.