Answer:
9/5
Explanation:
original fraction : x/y
new fraction = .9x/(.5y)
= 9x/5y
(9x/5y) / (x/y)
= 9x/5y * y/x
= 9/5
= 1.8
so it increased by 80%
e.g suppose we had 100/200 or 1/2
new fraction = 90/100 or 9/10
new ratio = (9/10) / (1/2)
= 9/5
That would be true because of momentum but the seat belt would slow this you would still hit the dash or a steering wheel's air bag system if it is equipped with one