Is breaking an egg an example of a phycial or chemical change? is cooking an egg an example of a phycial or chamical change?

There is a theory that indicates that dinosaurs became extinct when about 65 million years ago, a large asteroid hit the earth surface. dust caused by this collision blocked the sunlight reaching the earth's surface and many forms of life became extinct due to the cold. fearing this threat, how large the radius of an asteroid should you be looking for if the dangerous asteroid size is approximately the same as the one that killed the dinosaurs? available data suggests that about 18% of that asteroid's mass ended up as a dust spread evenly over earth after eventually settling out of the upper atmosphere. about 0.0180 g/cm^2 of dust, which is chemically different than the earth's rock, covered the earth's surface. typical asteroids have a density of about 1.9 g/cm^3. now that we know the size of the asteroid, how much energy was released during impact, assuming all of it was just the kinetic energy of the asteroid right before the impact?

The frequencies refer to the sample data collected from a population of interest when performing a hypothesis test comparing two or more population proportions.

12. ritu obtained a distinct image of a distant tree on the screen with the of a concave mirror.to find the focal length of the mirror she has to measure the distance between: (a) mirror and the tree. (b) screen and the tree.(c) mirror and the screen. (d) mirror and tree as well as between screen and the tree.