# WHICH TANK FILLS FIRST? ft. Simone Giertz | Summary and Q&A

952.7K views
November 15, 2017
by
Physics Girl
WHICH TANK FILLS FIRST? ft. Simone Giertz

## TL;DR

In a viral riddle, the question of which container fills up first is explored using Pascal's law and incompressible fluid, but many assumptions are left unanswered.

## Key Insights

• 🖤 Viral riddles often lack specific physical assumptions, making it difficult to definitively answer them.
• 👮 Pascal's law, which explains the transmission of pressure in incompressible fluids, is relevant to the riddle of the filling containers.
• 💄 The riddle's answer depends on many unknown variables, making it impossible to determine the definitive outcome.
• 🎨 Imperfections in materials and experimental design can affect the outcome of the experiment.
• ☠️ The experiment suggests that, ideally, all containers should fill up at the same rate.
• 🙂 Container four is likely to fill up slightly faster than container three in the given experiment.
• 🍃 The riddle is a trick question and intentionally leaves too many unknown variables.

## Transcript

Thank you to 23andMe for supporting PBS Digital Studios. Are we ready to try this? I think we're ready to try it. What do you think is going to happen? I honestly haven't thought about it. Do you know what's going to happen? Hey. I'm Dianna. You're watching "Physics Girl." And you may have seen this riddle before. It went pretty viral in 2016. ... Read More

### Q: How does Pascal's law relate to the riddle of the filling containers?

Pascal's law explains that a pressure change in a container will be transmitted equally throughout the entire fluid. It suggests that, in an ideal scenario, all containers would fill up at the same rate.

### Q: What assumptions were made in the experiment?

Assumptions included gravity pointing downwards, filling to the brim, and a slow trickle of water into the top of the containers.

### Q: Can the riddle be definitively answered with physics?

No, because the riddle leaves too many variables unknown, such as the accuracy of materials used and the speed of fluid flow.

### Q: How does the experiment compare to the riddle?

The experiment shows that, due to imperfections in the model, container four fills up slightly faster than container three. However, in an ideal scenario, both containers would fill up at the same rate.

## Summary & Key Takeaways

• The riddle asks which container will fill up first out of several containers.

• The experiment is conducted using containers and a model of the riddle to test predictions.

• Pascal's law is applied to explain that, ideally, all containers should fill up at the same rate, but imperfections and unknown variables make it impossible to determine the definitive answer.