例4-1已知：o=60 k rev/min F=(3i+4i+5k)×102m 求：立=？ 解：o=(60×2π/60)k=2成(rad/) 立=ōXF =2πk×(3i+4j+5k)×103 =(60-8m)×102 0.251i+0.188j(m/s)例4-1 已知： 60k rev / min   = r i j k m 2 (3 4 5 ) 10− = + +      求： v = ?  解： k    = (602 / 60) 2 k (rad /s)  =  v r    =  2 2 (3 4 5 ) 10− = k  i + j + k       2 (6 8 ) 10− = j − i      0.251i 0.188 j (m/s)   = − +