0.6-mm-diameter glass tube is inserted into water at 20°C in a cup. The surface tension of water at 20°C is o,
0.073 N/m. The contact angle can be taken as zero degrees.
The capillary rise of water in the tube is

the diagram which shows forces as either balanced = same speed or unbalanced = accelerarting

it's when something is going so fast it makes a loud noise, breaking the sound barrier, for example: a jet makes a loud noise, not only cause of the jet but because they reached a point where they went so fast that you can year the noise from various parts, kinda like a police car, lets say the car was going   so fast that you hear the siren of the cop car right next to you, but the car is probably a mile a way, it's cos the siren was next to you a few seconds if you understand me