distance and time for hockeys

Question

two air hockeys are 2m apart. one is struck and moves directly towards the other at 1 m per second. the other is struck 0.2s later and moves directly towards the first at 1.7 m per second find how far the first puck has moved when the collision occurs and how long it has been moving for

Answer 1

d=2m

h1=1mps

h2=1.7mps-.2sec

1.7*.2=.34m lost distance

1t+(1.7t)-.34=2m

" " =2.34=.87sec*1mps=.87m