99+688CBDBACCCDBDBDDCBAC19BD20BC21AB242450()ddm()L3050sg(1)30(2)30(3)30L30die1E1=mgdsin(2)3050vv^2=2ugsv=2ugs30mgL+29dsin=12mv^2+30E2E2=mgL+29dsinumgs30(3)E2E1Ldussin