To convert linear motion to circular motion, you can use a mechanism called a crank and slider mechanism. Here's how it works:

1. Crank: The crank is a rotating arm or disk that is connected to a rotating shaft. As the shaft rotates, the crank also rotates.

2. Slider: The slider is a linear sliding component that is attached to the crank. As the crank rotates, the slider moves back and forth along a straight line.

3. Connecting Rod: The connecting rod is a link that connects the crank to the slider. As the crank rotates, the connecting rod causes the slider to move back and forth along the linear path.

4. Circular Motion: As the slider moves back and forth along the linear path, the end of the connecting rod attached to the slider moves in a circular path. This circular motion is the desired output.

In summary, a crank and slider mechanism converts the rotary motion of the crank into linear motion of the slider, and by connecting the slider to the desired component through the connecting rod, you can obtain circular motion. This mechanism is commonly used in various machines and devices, such as engines, pumps, compressors, and many more.