An iron rod with diameter of 12cm
at 20°c is to be fixed into a steel
plate having
a hole
of
diameter 10cm
at same temperature.
To what Temperature must the steel
plate be heated in order for the
for
rod to Fix ?
[linear expansivity of the steel is 0.00001/K]​

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

answer(20) psi;