How many centuries would it take for humans originating in africa to travel to china some 1 km away? at a rate of 1 km per year.

28. a stone is projected at a cliff of height h with an initial speed of 42.0 mls directed at angle θ0 = 60.0° above the horizontal. the stone strikes at a, 5.50 s after launching. find (a) the height h of the cliff, (b) the speed of the stone just before impact at a, and (c) the maximum height h reached above the grou

What is the rate of change in a objects position?

Write down two additional questions about earth's magnetic field that will make your presentation more informative.