A body floating freely in a fluid, must obey the following laws known as laws of floatation:
(i) A body floats only if its weight is equal to the weight of fluid displaced by its immersed part.
(ii) For the body to float in upright position, the centre of gravity of the floating body and the centre of buoyancy of the fluid displaced by the immersed part of the body must lie on the same straight line.
1st law stated above is necessary for the body to float whereas the 2nd law stated above is necessary for the body to float in upright position.
The finger exerts a force of 84 N on the pinhead. The pinhead has an area of 6.0 × 10-5 m2 . Explain why the pin causes more pain in the man’s thumb than in his finger.