William Haynes

William Haynes on 3D Equilibrium: Hanging Plate 1 year, 11 months ago

Gave some feedback: Ready to use

William Haynes on Equilibrium of a rigid body: truss 2 years, 2 months ago

Saved a checkpoint:

Turned off debug mode (oops), and edited the ggb applet to turn off gridlines and scale.

William Haynes commented on 16. Equivalent Systems, Resultants 2 years, 7 months ago

Added question: equivalent force couple system on bracket

William Haynes on Equivalent Force-couple system: Bracket 2 years, 7 months ago

Gave some feedback: Ready to use

William Haynes on Equilibrium of a rigid body: beam and pulley 2 years, 8 months ago

Saved a checkpoint:

Properly italicized variables, reformatted advise.

William Haynes on Equilibrium of a rigid body: truss 2 years, 8 months ago

Saved a checkpoint:

When b=2.8, h=4, B=2, C=5, F=4, E=3, then Ay = 0, but  Numbas calculates it as Ay = -1.7763568394002505*10^(-15) and marks 0 wrong, because it calculates percent error to be 100 %

abs(0 - 0.00000000000002)/(0.00000000000002) = 1.

Added precround(Ay,6) in Marking settings to avoid this.  I don't know how to fix the root cause.

William Haynes on 13. Equilibrium of Rigid Bodies 2 years, 8 months ago

Saved a checkpoint:

Student reports that when A_y = 0, answer is not marked correct.