5-17 A 0.25 kg stone tied to a rope is swung to make a circular motion in a
vertical plane. If the circle is of radius
300 cm, what is the minimum uniform
speed of the stone that will keep the
rope taut? [Answer = 1.71 m/s]

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?

How would doubling the made of an object change the objects potential energy

In a voltaic cell, electrons flow from the (positive/negative) to the (positive/negative) terminal.