Answer:
0.139 rad
Explanation:
We use Snell's law
, where if
is the <em>refractive index</em> of the medium containing the <em>incident ray</em>,
would be the <em>incident angle</em>, and if
is the <em>refractive index</em> of the medium containing the <em>refracted ray</em>,
would be the <em>refraction angle</em>, which we want, so we do:

And finally:

We then insert our values:

I think its all four of them could be wrong but try all four !!!!!!
- 9.5 m/s^2
use the SUVAT method
0 = 38 + 4a