For question #2, your bernoulli equation is wrong, your speed need to be squared. You will have:
Put all this in yout bernoulli equation...
For question 1.. this question suck
Im not sure how to do it, i see 2 ways.. using bernoulli equation...
p1=1 atm = 101,325 kPa (P outside the can, it may be something else)
p2=8atm = 810,6 kPa (P inside the can)
v2=0 (Speed of the fluid inside the can initally... 0)
P= 1562 kg/m^3 (value I found on internet, you may have other numbers in your book)
(709,275 kPa/1562 kg/m^3)*2=v1^2
Or you can use the ''Conservation de la quantitée de mouvement'' (ehh not sure how to call it in english... conservation of quantity of velocity??) if its not bernoulli, its this but yeah I dont want to start doing integrations... but if the awnser's not good with bernoulli, look for this.
Hope it helps man, keep it up!!