A destroyer simultaneously fires two shells with different initial speeds at two different enemy ships. The shells follow the parabolic trajectories shown.
1)Which ship gets hit first?
Enemy 1
Enemy 2
Both ships are hit at the same time.

http://www.smartphysics.com/Images/P...Destroyer2.gif

Which enemy will get hit first, isn't that we need to know what the initial velocity is?

Actually, it depends on the maximum height the missile reaches. From the drawing, it seems they both get as high.

Without knowing this, or the initial y component, the answer cannot be obtained.

So none of the answers is correct?

It's not that, it's that we cannot say for sure, unless a little more information is given.

I'd say that since no further information is given, you're supposed to assume from the picture that they did, indeed, reach the same maximum height. It's unfortunate that the problem doesn't explicitly say that, but I'm not surprised.

As Unknown008 said, that means that they will hit the two ships simultaneously, because the time they remain in the air is independent of the horizontal component of the velocity; it depends only on the vertical component. Since they achieved the same maximum altitude, the two shells must have been fired with the same vertical component of their velocity.