[单选题]
A pendulum of length 50 cm is pua,q)a/tc;cyitt45k +w ijggt j3 13qylled 30 cm away 9vueap:etjqh62x+g(a ipb./ ,*skmx from the vertical axis and released from rest. What will be its speed at thpubs 2e/ . mai*:t (q+xvek9pax ,jg6he bottom of its swing?
