Which has the most gravitational potential energy? A. there isn't enough information to determine which has the most gpe
B. a 2 kg bird flying at a 10 meters per second
C. a 10 kg bird flying at 10 meters per second
D. a 10 kg bird flying at 15 meters per second
E. a 2 kg bird flying at 15 meters per second

see earlier answer

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 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