I have a shit teacher at a local community college who can't

take a ruler. scale the image until the length of the 9m/s vector becomes 9cm/inches/marks whatever your want.
then measure the resultant. thats it. 7 and 13

>>8458081
>use a ruler

What the FUCK. Drop out. Now, while you still can. What a fucking garbage school.

>>8458102
Explain to me why this is bad, please.

>>8458081
Use the law of sin/cosin, not too hard.

>>8458108
(not that guy but)
It's not, but it is sort of High School.

Solving geometrically is valid; I mean, slide rules use geometry to calculate and sent us to the moon.

Mostly though, resultant forces is not the kind of problem they would have in a college level physics class. One would use the projection of vectors in component form, or trigonometry to solve.
In the real world, geometric methods are often faster.
That is why your roof pitches are standardized.

Better solution
Use a protractor to measure the angles between 1 and 2
Then use trigo to solve the length

>>8458122
He probably hasn't learned that, given that his school is forcing him to do preschool-tier exercises.

>>8458134
Going with this for future study.

Appreciate all the help. I figured it out, learning different methods of solving this problem now, Again, thanks a lot.

>>8458122
But there's no given angle in the problem.

>>8458081
>Use a ruler to estimate the magnitude
You could do this without even using v2. Is this a joke?

>>8458081
holy shit kek I remember using rulers to measure vectors in high school physics

Look up "parallelogram of forces in link below, you then extrapolate (draw/mirror) these vectors given as a parallelogram and you measure the new diagonal that appears (and which will be the in direction of resultant)...If you draw each velocity as the lines legth ie 2ms as 2cm and 5ms as 5cm etc, the new diagonal (in direction of resultsnt force) its length will be the answer.in ms

https://en.wikipedia.org/wiki/Parallelogram_of_force

>>8458081
you need a scale factor.
mesure v1. its length is, for example, 4cm.
so 4cm is 9m/s, and 1cm is 9/4 m/s
measure unknown vector. lets say it turns out 8cm.
so the speed is 8 * 9/4 = 18m/s

>>8458704
OP, this.

File: 1478321728949.jpg (50KB, 500x737px) Image search: [Google]

50KB, 500x737px

>>8458137
fucken internet alpha.

File: 1384774555295.gif (400KB, 488x519px) Image search: [Google]

400KB, 488x519px

>>8458261

The approach is more simple
https://en.wikipedia.org/wiki/Cross-multiplication

measure the length of all arrows.
you find that the length of v1 for instance L1 = 10 cm and the length Lr of the resulting arrow is for instance Lr = 8 cm.
Then you have a table
L1 = 10cm <-> v1 = 9 m/s (1)
Lr = 8cm <-> vr = x m/s (2)

x is unknown. the x needs to be calculated now.

(1)/10 yields
1 cm <-> 9 m/s / 10 (3)

(3)*8 yields
8cm <-> 9 m/s / 10 * 8 (4)

Compare (2) and (4) and see
vr = 9 m/s / 10 * 8
or
vr = 9 m/s * 8 / 10

Look for "Rule of Three"