65 million years ago there was a mass extinction that is best known for killing the dinosaurs. there was also a large deposit of dust that contained substances only found in asteroids. what most likely killed off the dinosaurs?
an asteroid impact caused the sun to be blocked.
they were crushed by an asteroid.
the water supplies were polluted.
mammals evolved to be better competitors

At a certain instant after jumping from the airplane a, a skydiver b is in the position shown and has reached a terminal (constant) speed vb = 52 m/s. the airplane has the same constant speed va = 52 m/s, and after a period of level flight is just beginning to follow the circular path shown of radius ρa = 2330 m. (a) determine the velocity and acceleration of the airplane relative to the skydiver. (b) determine the time rate of change of the speed vr of the airplane and the radius of curvature ρr of its path, both as observed by the nonrotating skydiver.