Answers

2015-05-29T16:25:41+05:30
Existing coaster {h} = 2/3 m
new r c [h] = 3/5*h of existing one
                =3/5*2/3
                = 6/15 m or 0.4 m
0
2015-05-31T13:59:18+05:30
Let us consider that the new roller coaster's height is h.

The old one is  \frac{2}{3} of a meter.(it is a little short, but anyway)

 \frac{2}{3} (\frac{3}{5})
h=6/15 m
Or in decimals: h=0.40m

Conclusion:
1.The new roller coaster's height is 0.40m
0