# A plane drops a missile

## Homework Statement

a plane, traveling at 200 m/s in the X direction, drops a missile which has a constant acceleration of 7 m/s^2 at an angle 10 degrees below horizontal. If the plane is 1250 m high when it fires, how far (in the x direction) from where it was fired will the missile come down?

?

## The Attempt at a Solution

I have absolutely no idea how to start this problem... could I possibly break the 7m/s^2 into y and x components using cosine, sine and the angle of 350 (10 degrees below the horizontal)?

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Bystander
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Sounds like a start.

Sounds like a start.

okay...well how can I possibly keep going after that?

phinds
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okay...well how can I possibly keep going after that?
How about if you go that far and see if anything occurs to you.

How about if you go that far and see if anything occurs to you.

okay so I'm very much so struggling with this problem, but I tried to solve for the time when the missile will hit the ground

Δy=Voy(t) + ½ ay(t)2 → -1250= 0 (t) +½ (-1.2155) (t)2→ t= 45.35 seconds

is that correct so far?

Bystander
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Looks about right --- haven't got my calculator to check for dotting "i's" and crossing of "t's" as far as sin(10°), but definitely the correct ballpark and handling of the numbers. Please continue.

Looks about right --- haven't got my calculator to check for dotting "i's" and crossing of "t's" as far as sin(10°), but definitely the correct ballpark and handling of the numbers. Please continue.

after that, I plugged t into the equation Vfx= Vox +ax(t) → Vfx= 200+(6.894)(45.35) → and got 512.643 m/s for Vfx. I then multiplied the final velocity by the time (45.35 seconds) to get the Δx, which is 23248.3555 m . Is that correct?

Bystander
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That non-zero initial velocity tripped you up. How far does the missile travel if the initial velocity is zero? You did fine with the y-component.

so should it just be (6.894)*(45.35) then? With that I get an initial of 312.643 and then multiplied by time I get 14178.3555 m

Bystander