Question

A force of 90 Newtons is applied to a 20 cm2 surface.

Answer 1

The given question is incomplete. The complete question is:

A force of 90 Newton's is applied to a $20cm^2$ surface. The force applied is then increased by 5 Newton's and the surface is increased by $5cm^2$. What percentage does the outcome decrease by

Answer: The outcome decreases by 15.5 %

Step-by-step explanation:

Pressure is defined as the ratio of force per unit area.

$Pressure=\frac{Force}{Area}$

Case 1: $P_1=\frac{90N}{20cm^2}=4.5Ncm^{-2}$

Case 2: $P_2=\frac{95N}{25cm^2}=3.8Ncm^{-2}$

Decrease in pressure = $P_1-P_2$ = $(4.5-3.8) Ncm^{-2}=0.7Ncm^{-2}$

Percentage decrease = $\frac{0.7}{4.5}\times 100\%=15.5\%$

Thus the outcome decreases by 15.5 %