Question

If air is blow n with a straw under of the pans of a physical balance present in equilibrium position, then that pan.

• A. rises up
• B. remains in th e same position
• C. lowers down
• D. rises or lowers depending upon the velocity of air blown

Answer 1

Answer: (C)

lowers down

Answer 2

As the air is blown, the speed of air particles is more than the surrounding air. So, there would be an air pressure, $\frac{1}{2} \rho v ^{2}$. So the pan will lower down.