Thermal Detonator Yield[]
Having seen the episode again, I highly doubt this bridge is as large as Chaos Theory calculated. For example, two files Tanks with widths far lower than 12.6 metres (doing some scaling from here, the height to width ratio is about 1:3, making it 4.2 m) can fit on this bridge with a relatively small amount of space. 22.02 metre AT-TEs are also around the same size, if not larger, in the same holograms that CT used to scale the bridge.
Anakin = 23.09 px / 1.88 m
Bridge Width = 181.87 px / 14.8079514942 m
Bridge Width = 94.92 px / 14.8079514942 m
Bridge Length = 841.1 px / 131.215423533 m
Bridge Length = 142 px / 131.215423533 m
Bridge Width = 6 px / 5.54431367041 m
14.8079514942 * 131.215423533 * 5.54431367041 = 10772.7768114 m³
Fragmentation of rock is 8 j/cc
8 x 10772776811.4 = 86182214491.2 J
There were 13 grenades.
86182214491.2 / 13 = 6629401114.71 J
Barriss Offee Lifts Rock[]
Ahsoka is smaller than Barriss, who's 1.66 m. The old databank says she's 1.61 m, so I'll use that number.
Ahsoka = 570 px / 1.61 m
Rock Height = 326 px / 0.92080701754 m
Rock Width = 260 px / 0.73438596491 m
Rock Thickness = 136.03 px / 0.38422508771 m
0.92080701754 * 0.73438596491 * 0.38422508771 = 0.25982366658 m³
0.25982366658 * 2400 = 623.576799792 kg
Final Tally[]
Barris Feat = 0.623576799792 Tonnes (Class 1)
Thermal Detonator Yield = 1.58446489357 Tons of TNT (Building level+)