The value of the action potential -- how much greater the electric potential is inside the axon as compared to outside the axon -- is around 30 mV for the average neuron in humans. If the length constant of an axon is about 2 mm, at what distance LaTeX: xx (to the nearest tenth of a mm) from the end of the axon where this action potential is applied would the potential difference across the membrane become less than 1.6 mV (which is a very weak signal)

the total distance that martina travels that day is

(distance from home to mom's office) plus (distance from mom's office to school)

plus (distance from school to library) plus (distance from library to friend's house)

plus (distance from friend's house to martina's house).

(we don't know what any of these distance actually is.)

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