4 ms·
I initially thought that too but realized it was a meaningless concern. Even if you knew g, it wouldn't help because the pressure also depends on the thickness
by averagewall 9y ago
I initially thought that too but realized it was a meaningless concern.
Even if you knew g, it wouldn't help because the pressure also depends on the thickness of soil it's landing on, as well as its mechanical properties - like how much it's already been compressed. A hammer dropped onto concrete exerts more pressure than it does dropped onto sand.
Also, what's the shape of the footprint of the hammer? Error in that will be more than the difference between Earth and Mars gravity.
- peterwwillis 9y agoSee comments below for the link to their paper in Nature. Most relevant test case is "Impact test, Flexible boundary condition", where they give all the data on their test methodology. If you load Supplementary Data, Figure S9[1], it shows 400MPa at 1ms. It also shows (for the above test) around 9mm displacement at what looks like 365MPa? I suck at math so I'll let someone else figure out the force. [1] https://static-content.springer.com/esm/art%3A10.1038%2Fs41598-017-01157-w/MediaObjects/41598_2017_1157_MOESM1_ESM.pdf https://static-content.springer.com/esm/art%3A10.1038%2Fs415...