Identify the true statement. a. Our Universe is so old that there are no first-generation stars left in it. b. A fifth-generation star would have a smaller proportion of heavier elements than would a second-generation star. c. Dense regions of a nebula pull in surrounding material and therefore rotate slower. d. An accretionary disk eventually grows hot and massive enough to become a protostar, then a star.

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

inverse v=i*r

nice nice

false.

explanation:

this statement is false. after falling for 5 seconds, its speed will not be 100 m/s.