Easy-acceleration with unit vectors

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PEZenfuego
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Homework Statement



Handwritten solution sheet beneath a printed textbook problem: a graph of y (m) against x (m) shows a flying saucer at the origin with velocity 200j m/s and at (2000, 1000) m with velocity (200i - 100j) m/s, followed by printed parts A to D and handwritten notes.


r1=(0m)
r2=(2000i + 1000j)m
v1=(200j)m/s
v2=(200i-100j)m/s

Homework Equations


tantheta=vy/vx

v2^2=v1^2+2ax
v2=v1+at
x2=x1+v1t+1/2at^2

The Attempt at a Solution



Handwritten solution on lined paper for part c, finding the acceleration vector a from v2 squared minus v1 squared over 2 times the displacement, ending with a = 10i + 20j m/s squared; a vector diagram of v1, v2 and the change in velocity is shown at upper right.


Thank you for any help
 
find the saucer's acceleration in unit vectors and in terms of magnitude and direction.
 
PEZenfuego said:

Homework Statement



View attachment 50618

r1=(0m)
r2=(2000i + 1000j)m
v1=(200j)m/s
v2=(200i-100j)m/s

Homework Equations


tantheta=vy/vx

v2^2=v1^2+2ax
v2=v1+at
x2=x1+v1t+1/2at^2

The Attempt at a Solution



View attachment 50617

Thank you for any help
Are those kinematic equations for components of vectors, or for vectors themselves?
 
SammyS said:
Are those kinematic equations for components of vectors, or for vectors themselves?

If you click the first picture, you will have an understanding equal to mine. I'm sorry.
 
PEZenfuego said:
If you click the first picture, you will have an understanding equal to mine. I'm sorry.
Sorry for the slow response.

I should have been more direct with my earlier response.

The set of kinematic equations you have
(v2)2=(v1)2+2ax
(v2)=(v1)+at
x2=x1+(v1)t+1/2at2​
are valid for each component of displacement, velocity, and acceleration.

So you have two such sets of kinematic equations:
(v2)x2 = (v1)x2 + 2axx
(v2)x = (v1)x + axt
x2 = x1 + (v1)xt + 1/2axt2

(v2)y2 = (v1)y2 + 2ayy
(v2)y = (v1)y + ayt
y2 = y1 + (v1)yt + 1/2ayt2
​
 
SammyS said:
Sorry for the slow response.

I should have been more direct with my earlier response.

The set of kinematic equations you have
(v2)2=(v1)2+2ax
(v2)=(v1)+at
x2=x1+(v1)t+1/2at2​
are valid for each component of displacement, velocity, and acceleration.

So you have two such sets of kinematic equations:
(v2)x2 = (v1)x2 + 2axx
(v2)x = (v1)x + axt
x2 = x1 + (v1)xt + 1/2axt2

(v2)y2 = (v1)y2 + 2ayy
(v2)y = (v1)y + ayt
y2 = y1 + (v1)yt + 1/2ayt2
​

It makes sense now. thank you.
 
PEZenfuego said:
It makes sense now. thank you.
What did you get for answers?