An open glass tube is inserted into a pan of fresh water at 20 °c. what tube diameter is needed to make the height of capillary rise equal to four times the tube diameter? state all assumptions.

The tube diameter is 2.71 mm.

Explanation:

Given:

Open glass tube is inserted into a pan of fresh water at 20°C.

Height of capillary raise is four times tube diameter.

h = 4d

Assumption:

Take water as pure water as the water is fresh enough. So, the angle of contact is 0 degree.

Take surface tension of water at 20°C as N/m.

Take density of water as 100 kg/m3.

Calculation:

Step1

Expression for height of capillary rise is gives as follows:

Step2

Substitute the value of height h, surface tension, density of water, acceleration due to gravity and contact angle in the above equation as follows:

m.

Or

d=2.719 mm

Thus, the tube diameter is 2.719 mm.

it was a fall down when it happens

explanation: