Question

Which creates more pain when a needle tip with 0.2mm^2 area is applied
4N resultant force and a nail tip with 0.5 cm^2 area is applied 20 N resultant force. Write conclusion with calculation.

Answer 1

Here, forceo n the phonogram needle, F=1.2N

radius of the circular needle, r=0.1mm=0.1×10−3m

area of cross-section of the needle, A=πr2

=3.142×(0.1×10−3)2=3.142×10−8m2

pressure exerted on the record in Pa. P=PA

=(1.2N)(3.142×10−8m2)=382×105Nm□

pressure exerted on the record in atm

382×105Nm21.013×105Nm2atm

=378atm