a) Define the term surface tension

(b) Calculate the force required to lift a needle 4cm long off the surface of water if the surface tension of water is 7.3 x 10\(^{-4}\) NM\(^{-1}\)

 

DerickCO101

3 years ago

To calculate the force required to lift the needle off the surface of water, we need to use the equation:

F = T * L

Where F is the force required to lift the needle, T is the surface tension of water, and L is the length of the needle in contact with the water surface.

Given, the length of the needle is 4 cm, which is equal to 0.04 meters, and the surface tension of water is 7.3 x 10^-4 Nm^-1.

So, putting these values in the above equation, we get:

F = (7.3 x 10^-4 Nm^-1) * (0.04 m)
= 2.92 x 10^-5 N

Therefore, the force required to lift the needle off the surface of water is 2.92 x 10^-5 N