Hooke's law describes a certain light spring of unstretched length 34.2 cm. when one end is attached to the top of a doorframe and a 7.38 kg object is hung from the other end, the length of the spring is 40.0 cm. (a) find its spring constant. kn/m (b) the load and the spring are taken down. two people pull in opposite directions on the ends of the spring, each with a force of 198 n. find the length of the spring in this situation. m

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

distance = 150m

displ = root (50 ^2 + 100^2)

root(2500+10000)

root 125000