The force on a phonogram needle is 1.2newton.the point has acircular cross section of radius 0.1 millemeter. What pressure does it exert on the record in
Pa
Atm
The force on phonogram needle is, F = 1.2 N.
The point has a circular cross section of radius, r = 0.1mm = 10-4 m
⇒ Area = π r2 = 3.14 × 10-4 m2
Pressure = F/A
Please substitute the values from above and get the desired answer!