2D Kinematics Problem dealing with acceleration

[Element1674]

Homework Statement

" An airplane turns slowly for 9.2s horizontally. The final velocity of the plane is 360km/hr [N]; the average acceleration during the turn is 5.0m/s^2 [W]. What is the initial velocity of the plane?"

Homework Equations

a=ΔV/t

The Attempt at a Solution

at=Δv
(5.0m/s^2[W])(9.2s)=Δv
46m/s[W]=Δv

...then from here I get stuck. I know the horizontal component of the plane at the end (final) is 0 and the vertical component (final) is 360km/hr, but this doesn't help me find any obvious solution.

 

[haruspex]

I know the horizontal component of the plane at the end (final) is 0 and the vertical component (final) is 360km/hr, but this doesn't help me find any obvious solution.

I assume you mean EW, NS, not horizontal and vertical.
You have successfully calculated the change in velocity (a vector), and you know the final velocity, another vector. You are trying to find the initial velocity, a third vector. What, as vectors, is the relationship between the three?

 

[Element1674]

I think I have it!
ΔV=Vf-Vi
Vf-Δv=Vi

I know the x and y components of each Δv and Vf so I set up 2 separate equations:
Vfx-ΔVx=Vix
(Same idea with y)

Then use Pythagorean with Viy and Vix to find Vi, find the angle using trig, etc?

 

[rude man]

I have an answer I'm hoping to compare with the result of the thread, if any.

 

[haruspex]

I think I have it!
ΔV=Vf-Vi
Vf-Δv=Vi

I know the x and y components of each Δv and Vf so I set up 2 separate equations:
Vfx-ΔVx=Vix
(Same idea with y)

Then use Pythagorean with Viy and Vix to find Vi, find the angle using trig, etc?

That'll work.

 

[rude man]

I think I have it!
ΔV=Vf-Vi
Vf-Δv=Vi

I know the x and y components of each Δv and Vf so I set up 2 separate equations:
Vfx-ΔVx=Vix
(Same idea with y)

Then use Pythagorean with Viy and Vix to find Vi, find the angle using trig, etc?

Any plans for the acceleration a in direction W?