Numericals on Pressure

Numericals on Pressure

Open Ended

A 50 kg girl wearing high heel shoes balances on a single heel.The heel is circular with diameter of 1cm. What is the pressure exerted by the heel on the floor?

Solution

Area of heel= 7.85 x 10^-5 m²

F= mg= 490N

P= F/A= 6.24 x 10⁶ Pa

Open Ended

A vertical off shore structure is build to withstand a maximum stress of 10⁹ Pa.Is the structure suitable for putting up on top of an oil well in the ocean? Take the depth roughly upto 3 km and ignore ocean currents.

Solution

P=hgρ = 3 x 10³ x 10³ x 9.8= 2.94 x 10⁷ Pa

As maximum allowable stress is greater than the pressure of sea water, structure is suitable.