Helen is incorrect, the pressure decreases by greater than 20% and percent decrease is 23.80%.
What is the percentage?
It's the ratio of two integers stated as a fraction of a hundred parts. It is a metric for comparing two sets of data, and it is expressed as a percentage using the percent symbol.
Pressure before the change:
Area = 20 square cm = 0.002 square meters
P = 70/0.002 = 35000 N/m²
The force is increased by 10 newtons. The area is increased by 10cm²
New pressure = (70+10)/(0.003) = 26,666.667 N/m²
Percent decrease = [(35000 - 26,666.667)/35000]×100
= 23.80% (pressure decrease by 23.80%)
Thus, Helen is incorrect, the pressure decreases by greater than 20% and percent decrease is 23.80%.
Learn more about the percentage here:
brainly.com/question/8011401
#SPJ1
