The Earth rotates around itself and revolves around the Sun. Our solar system revolves around the center of our galaxy and our galaxy is moving in some way throughout the universe. If you took into account all this, how fast would you be going just standing still? Can we even calculate such a value giving that there is no static point in the universe to which we can measure ourselves against?
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Earth is moving around sun in an orbit with mean radius 1AU. Time of one revolution is 1 year . Thus, its speed is $$ v \approx 2 \pi \dfrac{1AU}{1year} = 30km/sec $$ Sun moves around galactic center at a speed of $ v'=220km/sec$. Thus, when you are standing still on Earth,you can have a velocity of $v'+v$ $\textit{with respect to center of Milky way galaxy}$. This value lies in the range of $[220-30,220+30] km/s$ (since velocities are added vectorially). This value is used when you can make an assumption that our galaxy is at rest.
From cosmological point of view, our galaxy is moving around other galaxies. An absolute frame of reference can be $\textit{ Cosmic background radiation}$, which is supposed to be constant throughout the space. With CMBR as reference frame, the speed of Earth measured by COBE(cosmic background explorer), is $360+/- 20 km/s$.
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