Does the speed of a sound wave ever change in a gas? what is the speed of a sound wave?

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?

An object dropped from cliff falls with a constant acceleration of 10 metre per second square find its speed of two seconds after it was dropped

Which one of the following represents the reduced forms of the two major electron carriers? nadh and fadh2 nad+ and fadh2 nad+ and fad nadh and fad