Hey, hey, fanta here. Time for another calc.
Context[]
A girl named Mine shields a child from being hit by a truck, not moving an inch and completely crushing the bumper and engine in the process. Youtube.
Calculation Information[]
While the feat is a visual novel feat, the CG background paints the area as a residential area so the truck itself is (likely) a Pickup Truck, which can weigh over 4082.3kg. Blue Archive itself is "loosely" based on modern japan and was first released in Japan, so I'll assume the speed limits of Japan; which is 60 km/h (16.6666 m/s) for anywhere that isn't a divided national highway. I'm going to attempt to get the Force/LS of Mine stopping in front of this pickup truck, forcibly stopping it and her not being moved; I'll assume she stopped the truck in 1s due to, again, being a visual novel feat as a reasonable low-ball. Edit: Work formulas (Work = Force/Displacement) are a thing. So... The average length of a pickup truck is 16.3 feet or 4.96824m; I'll assume Mine did half of this length for the sake of this calc did to, again, this feat being a visual novel feat.
The truck's bumper was said to be completely crushed, so I think LS via compressive strength might be viable here too, so trying that as well. I'll assume the diameter of the "crushing" is equal to the width of Mine's shoulders, and go on from there. Mine is 1.68m 17yr old, so her shoulder width is 0.4m per Human Proportions Calculator. Truck bumpers are made out of steel, pipe and aluminum. I will assume aluminum and its compressive strength here; which ranges from 40 MPa to over 500 MPa-thus, I'll use 270 MPa as the in-between due to the nature of the feat.
Calculation[]
Stopping the Truck[]
- KE - 0.5*4082.3kg*(16.666 m/s)^2 = 566940.753 joules, or 566.940753 kilojoules (9-B) [Wall level]
- Displacement - 4.96824m/2 = 2.48412m
- Work - 566940.753 joules/2.48412m = 228225.993 newtons | 228225.993 newtons / 9.81m/s^2 = 23264.6272 kilograms, or 25.6448617 Tons (Class 25) (Approved)
- Deceleration - 16.666/1 = 16.66600 m/s^2
- Force - 16.66600 m/s^2*4082.3kg = 68035.6118 newtons | 68035.6118 newtons / 9.81m/s^2 = 6935.3325 kilograms, or 7.64489546 (Class 10) (Approved)
Mine crushing the bumper[]
- Diameter - 0.4m
- Radius - 0.2m
- Area - π*(0.2m)^2 = 0.125663706 m^2
- Compressive Strength of Aluminum - 270 MPa = 270000000 N/m^2
- Force - 0.125663706 m^2 * 270000000 N/m^2 = 33929200.6 newtons | 33929200.6 newtons / 9.81 m/s^2 = 3458634.11 kilograms, or 3812.4915 Tons (Class M) (Approved)