A spring with a force constant of 5.5 N/m has a relaxed length of 2.47 m. When a mass is attached to the end of the spring and allowed to come to rest, the vertical length of the spring is 3.78 m. Calculate the elastic potential energy stored in the spring.

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 two required components for a generator are

If an athlete runs once around a track, back to the starting line, her average velocity is zero. true or false?