Fluid Mechanics: Can't Solve Exercise 3?

[JSBeckton]

http://img90.imageshack.us/img90/9176/img062iz2.jpg

I am having trouble starting exercise 3. If both jets have the same velocity,area, and the same density what would cause the cart to move? If they are mean that the cart is given an intial velocity and I need to give an expression fot the acceleration and velocity I am thinking that the two forces would be equal and opposite and therefore cancel each other out. In that case the velocity remains constant and the acceleration is 0 due to no friction.

Can anyone tell me if there is something I am missing?

Thanks

 

[hxtasy]

Well if they are just asking for an expression for U(t) and a(t) so even if they cancel out there is still a mathematical model that it will follow.


But either way if you find the answer can you post it this is interesting?