A ball of mass 10 kg is dropped from the roof of a building of height 138 m strikes the ground with a speed V1. A second ball of mass 25 kg is dropped from the height 51 m and strikes the ground with a speed v2. What is the ratio K/K2, where K, and K2 are the kinetic energies of the first and second ball at the moment when they hit the ground?

How would you place two electrons on a sphere of radius r so that the electrostatic potential energy is minimized. how would you place three electrons to solve the same problem.

As a car drives with its tires rolling freely without any slippage, the type of friction acting between the tires and the road is 100) a) static friction. b) kinetic friction. c) a combination of static and kinetic friction. d) neither static nor kinetic friction, but some other type of friction. e) it is impossible to tell what type of friction acts in this situation.

Your target variable is δf, the magnitude of the difference in frequency between the waves emitted from the sonar device and the waves received by the device after reflecting off the whale. write an expression for δf in terms of the relevant frequencies using the subscript notation introduced above.