Question is wrong?

You're an idiot, 45 degrees is way off. Southern Poland isn't that far from London.

>>8246354
south pole

>>8246366

fell for the bait.

besides, it shouldnt matter how far away you are should it?

Wouldnt it have the same launch velocity regardless of the angle you launch it at?

>>8246375

Its poorly worded.
try
>What angle should it be so that the missile can still reach its target with the minimum possible launch velocity?

Does it have wings?

>>8246384

i would assume not, but considering that I keep getting 45 degrees i might not be correct

What is your working to get 45?

>>8246386
Dude, I am in uterecht, dont be that rockety, come to me and we can get warhead there and rocket out, its safer, you will hit me and they wont trust me, I dont want nuclear war around, I am slowly transforming them to tuxation, wait for cortena if it does correct self to cornetto we can live

ballistic missiles work by going into an orbit right? So wouldn't the larger angle mean a higher orbit and a smaller velocity? I would choose 20 degrees, and by OP's logic the angle closest to 45 degrees is correct so the answer would also be 20.

File: received_845215932245221.jpg (263KB, 1440x1920px) Image search: [Google]

263KB, 1440x1920px

>>8246394

I split it up into components, a radial one with 9.81m/s^2 of acceleration downwards, and an angular one with zero acceleration - like a high school question but in polar coordinates

I then expressed the velocity in terms of the initial angle (pic is similar), and found the minimum point via calculus. I got 45 degrees consistently.

The only thing I can think of is that maybe you cant do the component velocities thing unless youre in cartesian coords?

>>8246341
so, if you use the curvature of the earth, and create an x and y axis, you can get an expression in terms of x,y,g,theta, and v0.

You know what x,y,g are, you have options for theta as choices.

Whichever one gives you the lowest v0 is the correct answer.
In this case, it's 20 degrees.
If 45 degrees was a choice, it would be the correct answer.

Since the question has 2 B's as choices, there's no way for the prof to know which "B" students selected, and the question should be discarded.

>>8246341
> Surely its 45 degrees? Is there a missing 4 in A or something?

I would interpret the question as "which of the following four launch elevations results in the minimum launch speed". In which case, the answer would be 20 degrees, because that's the closest to 45 degrees.

The higher the launch angle, the longer it stays airborne, the more time it has to reach the target, thus the lower the needed launch speed.