Which type of motion is described as moving backwards and forwards, like the needle of a sewing machine?

The type of motion that is described as moving backwards and forwards, akin to the needle of a sewing machine, is known as reciprocating motion. This motion involves a straight-line movement in one direction, followed by a straight-line movement in the opposite direction.

In the case of a sewing machine, the needle moves downwards to puncture the fabric and then rises back up to repeat the cycle. This repetitive back-and-forth action is characteristic of reciprocating motion, which is often found in various machines and mechanisms such as pumps and pistons, where the components must move in alternating directions.

Understanding reciprocating motion is crucial in design technology as it relates to the functioning of numerous devices that require precision and efficiency in their operation.