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# Physics problem：?

I don't know how to find the period and (b), thanks

### 2 Answers

- billrussell42Lv 72 months agoFavourite answer
6360 m/s, 9840 km ?? a bit blurry.

circumference of orbit is πd = 2πr = 2π(9,840,000 m) = 61,830,000 m

61,830,000 m / 6360 m/s = 9721 sec

1 circumference = 2π rad

1 circum / 9721 s x (2π rad/circum) = 0.0006463 rad/s

(45º/360º)61,830,000 m = 7,729,000 m

- oubaasLv 72 months ago
a

angular speed ω = V/r =6,360 m/sec / (9.84*10^6) m = 6.463*10^-4 rad/sec = 2PI/Tperiod T = 2PI/ ω = 6.2832*10^4/6.463 = 9,722 sec bdistance = 2PI*r/8 = 9840*3.1416/4 = 7,728 km