[Review] Start on Projectile SRS

[samm82]

So far, I added the Goal Statements, Assumptions, TMs, DDs, GD, and IMs, and I think this is enough to review. In particular, I'm not 100% if the concepts/unitals are defined clearly enough/if I'm using the default physics concepts too heavily. Also, I think technically the velocity entered is speed since it is a scalar with units (m/s), but since an angle is specified as well, I think it might be OK?

Closes #1430, closes #1431, closes #1493, closes #1577, closes #1584, closes #1617, closes #1620, closes #1621, closes #1622, and closes #1623

[bmaclach]

I thinks this looks good. I don't think you are using the default physics concepts too heavily - I would even say that some of the Unitals you define in the projectile example belong in drasil-data (initial and final velocity, x and y components of velocity, these are very general and could apply to many examples).

There's definitely some inconsistency with regards to quantities being vector or scalar. In the final velocity GD, for example, the equation is wrong because somehow the acceleration vector is turning into a scalar. I think final and initial velocity should both be defined as vectors? With the Distance GD as well everything (except time) should be a vector. But then elsewhere initial velocity is used as a scalar (i.e. in the Distance (refined) GD). Probably this means we should have two unitals: one for the initial velocity vector and one for the initial speed scalar. In the Air Time and Distance (refined) GDs, the denominator should really be the magnitude of the acceleration vector. There's also vector/scalar mismatch in the DDs. v_x is really the magnitude of v times cos(theta), and similarly for v_y.

Some other minor comments:

• instead of "angle of projectile", I think the description for theta should be "angle at which projectile is launched" or simply "launch angle"
• d_offset is unitless but based on the equation for it, it should have units of metres

[samm82]

Barring any unforeseen issues, Projectile is ready to be launched! (Pun very much intended) @smiths @JacquesCarette

[samm82]

@smiths Other than the Hibbeler reference - I totally forgot to ask in the meeting! Would I be able to grab the book today?

[smiths]

I just sent you an e-mail about the book. 😄 Please come by my office to pick it up.

[smiths]

I think we are in a good spot to merge Projectile in. We have a good initial draft. We can make future changes with this as a starting point.

[smiths]

Since @JacquesCarette will not be able to review this for at least a week, and possibly longer, I've merged it into master. We can create new branches as we continue to develop certain aspects of Projectile, such as the code generation.