T
h
e
s
p
e
e
d
o
f
l
i
g
h
t
i
n
g
l
a
s
s
i
s
a
b
o
u
t
2
×
10
8
m
/
s
e
c
.
U
s
e
t
h
e
f
o
r
m
u
l
a
,
t
i
m
e
=
d
i
s
tan
c
e
s
Match the items on the right to the items on the left.
Check
OK
STEP1
STEP2
STEP3
STEP4
