Q&A

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posted 1y ago by celtschk‭  ·  edited 1y ago by celtschk‭

#2: Post edited by celtschk‭ · 2021-08-14T14:03:47Z (about 1 year ago)
• If you are accelerating while running on Earth, actually you are also accelerating Earth in the opposite direction. However for a given force, the acceleration is inversely proportional to mass, therefore when some $60\\, m kg$ person accelerates by, say, $1\\, m m/s^2$, then Earth, which has a math of about $6\cdot 10^{24}\\, m kg$, will only accelerate with $10^{-23}\\, m m/s^2$, far to low to actually notice (if accelerating for a second, the change of speed of the Earth will be so that in about three years it moved by the diameter of a proton — provided you kept running at the final speed in the same direction for the whole three years).
• If you are accelerating while running on Earth, actually you are also accelerating Earth in the opposite direction. However for a given force, the acceleration is inversely proportional to mass, therefore when some $60\\, m kg$ person accelerates by, say, $1\\, m m/s^2$, then Earth, which has a mass of about $6\cdot 10^{24}\\, m kg$, will only accelerate with $10^{-23}\\, m m/s^2$, far to low to actually notice (if accelerating for a second, the change of speed of the Earth will be so that in about three years it moved by the diameter of a proton — provided you kept running at the final speed in the same direction for the whole three years).
#1: Initial revision by celtschk‭ · 2021-08-14T14:02:40Z (about 1 year ago)
If you are accelerating while running on Earth, actually you are also accelerating Earth in the opposite direction. However for a given force, the acceleration is inversely proportional to mass, therefore when some $60\\,\rm kg$ person accelerates by, say, $1\\,\rm m/s^2$, then Earth, which has a math of about $6\cdot 10^{24}\\,\rm kg$, will only accelerate with $10^{-23}\\,\rm m/s^2$, far to low to actually notice (if accelerating for a second, the change of speed of the Earth will be so that in about three years it moved by the diameter of a proton — provided you kept running at the final speed in the same direction for the whole three years).