The higher the pressure, the higher boiling point of water. At lower the pressure, the boiling point of water comes down. So, the lower pressure inreases the boiling resulting more evaporation. As we go higher in altitude, the atmospheric pressure decreases. This results in decreasing the boiling point at higher altitude and increase in boiling of water. In fact, at the sea level ,the the sea water boils at 100 degree C where atmospheric pressre is normal. However , the boiling takes place at a lower temperature at the top of a mountain due to low pressure. In other words the boling is faster at the top of a mountain than that at its foot.
Answer:
27 blocks
Explanation:
First, the expression to use here is the following:
P = F/A
Where:
P: pressure
F: Force exerted
A: Area of the block.
Now , we need to know the number of blocks needed to exert a pressure that equals at least 2 atm. To know this, we should rewrite the equation. We know that certain number of blocks, with the same weight and dimensions are putting one after one over the first block, so we can say that:
P = W/A
P = n * W1 / A
n would be the number of blocks, and W1 the weight of the block.We have all the data, and we need to calculate the area of the block which is:
A = 0.2 * 0.1 = 0.02 m²
Solving now for n:
n = P * A / W1
The pressure has to be expressed in N/m²
P = 2 atm * 1.01x10^5 N/m² atm = 2.02x10^5 N/m²
Finally, replacing all data we have:
n = 2.02x10^5 * 0.02 / 150
n = 26.93
We can round this result to 27. So the minimum number of blocks is 27.
Answer:
decrease
Explanation:
Addition of a lubricant such as oil to a surface will decrease friction. This makes the surface more greasy or slippery. This is very much efficient in machines, for example.
Answer: precise
Explanation:
Three different people weight a standard mass of 2.00 g on the same balance. Each person obtains a reading of 2.32 g for the mass of the standard. These results imply that the balance that was used is precise.
Precision can be defined as the closeness of measured values to each other, for a measuring equipment it is the closeness of the values of readings obtained at different times to each other. It does not necessarily means the measurements are accurate(closeness to the actual value). Therefore, in the case above where three different people measured the same mass on the same balance, and each of them obtained the same value which is different from the standard value. We can say the balance used is precise because the three readings are the same.
