Question

Mars has an average atmospheric pressure of \(0.007\) atm. Would it be easier or harder to drink from a straw on Mars than on Earth? Explain. [Section 10.2]

Short answer

It would be harder to drink from a straw on Mars than on Earth. This is because the atmospheric pressure on Mars is significantly lower (0.007 atm) than on Earth (1 atm), resulting in a smaller pressure difference when creating a partial vacuum inside the straw. The smaller pressure difference means less force is pushing the liquid up the straw, making it more difficult to drink on Mars.

Step-by-step solution

Understand the concept of drinking from a straw

When drinking from a straw, we create a partial vacuum inside the straw by sucking the air out of it. This causes a pressure difference between the inside of the straw and the atmosphere. The greater the difference, the stronger the force that pushes the liquid up the straw and into our mouths.

Compare the atmospheric pressures

Earth's atmospheric pressure is 1 atm, while Mars' atmospheric pressure is 0.007 atm, which is much lower.

Consider the pressure difference

On Earth, when we create a partial vacuum inside a straw, the pressure difference comes from the 1 atm pressure pushing on the liquid. The liquid then rises into the straw due to this difference in pressure. On Mars, the atmospheric pressure is significantly lower at 0.007 atm. When we create a partial vacuum in the straw, the pressure difference between the inside of the straw and the outside atmosphere will be much smaller compared to Earth. This is because the pressure pushing on the liquid from the outside is much lower than on Earth.

Final conclusion

Since the pressure difference is smaller on Mars, it would be harder to drink from a straw compared to Earth. The lower pressure difference means less force is pushing the liquid up the straw, making it more difficult to drink on Mars.