* 5K walk/run: This is a common distance for races and walks.
* 5kW (kilowatts): This is a unit of power, often used to measure the output of electrical devices.
* 5K word count: This could refer to a target word count for a piece of writing.
Could you clarify what you mean by "5K w"? This will help me understand your question and give you a more accurate answer.