Discover Questions

How many particles are in 1 litre of oxygen gas if density of oxygen gas is .429? A Line L is tangent to the curve y = -x2 at some point P and to the curve y = x2 - 6x +13 at some point Q. What is the equation for L? Compared to the length of a football field what is 1000ft? Why do we exist? can we live on mars? can we see Oxygen? Can lightning strike on a plane? Can I learn physics by putting the essence of time in a jar?