The pressure exerted by a phonograph needle on a record is surprisingly large. If the equivalent of 0.600 g is supported by a needle, the tip of which is a circle 0.240 mm in radius, what pressure is exerted on the record in N/m2?

Explanation:

Hello,

In this case, since pressure is defined as the force applied over a surface:

We can associate the force with the weight of the needle computed by using the acceleration of the gravity:

And the area of the the tip (circle) in meters:

Thus, the pressure exerted on the record turns out:

Which is truly a large value due to the tiny area on which the pressure is exerted.

Best regards.