In the Bohr model of the atom, the ground-state electron in hydrogen has an orbital speed of 2190 km/s. The mass of an electron is 9.11×10−31kg. What is its kinetic energy? Express your answer using three significant figures.

The combining of light nuclei is called blank. blank as in not actually blank. you know what im tryin to say.

An electron moves with a constant horizontal velocity of 3.0 × 106 m/s and no initial vertical velocity as it enters a deflector inside a tv tube. the electron strikes the screen after traveling 26 cm horizontally and 19 cm vertically upward with no horizontal acceleration. what is the constant vertical acceleration provided by the deflector? (the effects of gravity can be ignored.)

It's time for santa to deliver his presents. assuming he delivers presents all over the world, he has to travel about 75,000,000 miles. if he travels east to west, he can use the time zones to make christmas day last 31 hours. what speed, in miles per hour, must santa fly to get all of his presents delivered?