There are z protons in the nucleus of an atom, where z is the atomic number of the element. an α particle carries a charge of +2e. in a scattering experiment, an α particle, heading directly toward a nucleus in a metal foil, will come to a halt when all of the particle's kinetic energy is converted to electric potential energy. in such a situation, how close will the center of an α particle with a kinetic energy of 6.4 x 10-13 j come to the center of a gold nucleus (z = 79)?

The percent efficiency of a machine can never be 100% (or greater), because in the real world some energy is always converted into a. heat b. work c. input force d. output force

This is important 1. what happens to the speed of molecules in water vapor when it condenses to form a liquid? (2 points) the molecules slow down. the molecules speed up. the molecules slow down and then speed up. the molecules speed up and then slow down. 2. how might human activities change to compensate for a decrease in water supplies? (2 points) humans might build a factory. humans might build drainage systems. humans might extract more water from the ground. human behavior does not change because of the water cycle. i'll be grateful if anyone can answer these 2 questions !

Awind turbine is rotating counterclockwise at 0.5 rev/s and slows to a stop in 10 s. its blades are 20 m in length. (a) what is the angular acceleration of the turbine? (b) what is the centripetal acceleration of the tip of the blades at t=0s? (c) what is the magnitude and direction of the total linear acceleration of the tip of the blades at t=0s?