While spinning down from 500.0 rpm to rest, a solid uniform flywheel does 6.0 kJ of work. If the radius of the disk is 1.2 m, what is its mass? (a) 7.9 kg
(b) 7.0 kg
(c) 5.2 kg
(d) 6.1kg

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

find the surface area of the sphere to the nearest square unit. use a calculator.

a. 254 in.2

b. 64 in.2

c. 127 in.2

d. 1,018 in.2

it's