we have
ArarrB
u=v_1" " v=v_2" let the distance be "s" and accln "a
using " "v^2=u^+2as
color(blue)(v_2^2=v_1^2+2as)--(1)
ArarrC
u=v_1" " v=v_c" the distance is "s/2" and accln "a
using " "v^2=u^+2as
v_c^2=v_1^2+2as/2
=>color(blue)(v_c^2=v_1^2+as)--(2)
eqn (2) xx2" and rearrange"
2v_c^2=2v_1^2+2as
color(red)(2v_c^2-2v_1^2=2as)
substitute into" "(1)
v_2^2=v_1^2+color(red)(2v_c^2-2v_1^2)
now rearrange for " "v_c
v_2^2=2v_c^2-v_1^2
v_c^2=(v_2^2+v_1^2)/2
v_c=sqrt((v_2^2+v_1^2)/2)