Large and small particles are found mixed in a fast moving stream. What type of erosion is this?

Stream Erosion and Deposition

Explanation:

water is a very important mechanism for both erosion and deposition. Water flow in a stream is primarily related to the stream's gradient, but it is also controlled by the geometry of the stream channel. Water flow velocity is decreased by friction along the stream bed, so it is slowest at the bottom and edges and fastest near the surface and in the middle.