A particular corrective covert lens has a focal length of 20cm . If the object is place at a distance of 40cm A) what is the distance at which image formed?

B) calculate the magnification of the image formed?

the answer is f1 and d2 because if you put equal force on those two points the beam would balance trust me on this

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

it's a b and