Chapter 10&ll 质点的转动 10-1.Angular Quantities(P235-237) 1.Angular position 0 p235: We measure the angular position 6 of this line relative to a fixed direction (x) △s △0 Unit of: radian(rad)弧度 0Chapter 10&11 质点的转动 10-1. Angular Quantities (P235-237) r s  = Unit of : radian( rad) 弧度    o r s x s We measure the angular position  of this line relative to a fixed direction (x). 1.Angular position  p235: