1. find the surface area of a sphere with a circumference of 86 cm. round to the nearest tenth. a. 2,354.2 cm2
b. 1,177.1 cm2
c. 187.3 cm2
d. 13.7 cm2

2. a balloon has a circumference of 16 cm. use the circumference to approximate the surface area of the balloon to the nearest square centimeter. a. 804 cm2
b. 326 cm2
c. 256 cm2
d. 81 cm2

1.d

2.b

3. a

4. b

5. b

6. d

7. c

8. a

9. a

10. b

11. b

12. b

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