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BEST IELTS Writing Task 1 Academic, 18th November
IELTS ACADEMIC WRITING TASK 1
IELTS ACADEMIC WRITING TASK 1
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. Summarise the information by selecting and reporting the main features, and make comparisons where relevant.
SAMPLE ANSWER
The diagram shows that a mechanical arm functions in a way that is very similar to the human arm. The mechanical arm has joints just like a human arm, each of which plays a similar role. To start with, the mechanical arm is fixed to a base at the shoulder. The base is usually stationary, but occasionally the arm is fixed to a movable base. A pivot between the similar and the base enables the whole arm to rotate.
The shoulder functions just like a human shoulder, raising and lowering the arm. The elbow in the middle of the arm allows further movement and gives the whole apparatus flexibility. In the same way that the human wrist allows the hand to move, the wrist on the mechanical arm allows the gripper, or any alternative end-effector, to both flex and rotate.
Each of the joints in the mechanical arm is connected to a separate motor, which is in turn connected to a computer. The computer controls the motors, ensuring perfect precision.
The gripper can be replaced with various end-effectors for specific applications. A mechanical arm may be fitted with an end-effector that sprays paint, drills holes, or welds metal, for example. In-built pressure sensors control the force that the gripper or alternative end-effector applies.
