You are at the controls of a particle accelerator, sending a beam of 1.80 x 10^7 m/s protons (mass m) at a gas target of an unknown element. Your detector tells you that some protons bounce straight back after a collision with one of the nuclei of the unknown element. All such protons rebound with a speed of 1.50 x 10^7 m/s . Assume that the initial speed of the target nucleus is negligible and the collision is elastic.
(a) Find the mass of one of the nuclei of the unknown element. Express you answer in terms of the proton mass m.
(b) What is the speed of the unknown nucleus immediately after such a collision?

11m

3000000 m/s

Explanation:

= Mass of proton

= Mass of unknown element

= Velocity of proton =

= Velocity of rebound =

As the energy of the system is conserved we have

Mass of the unknown element is 11m

As the momentum of the system is conserved

The speed of the unknown nucleus immediately after such a collision is 3000000 m/s

most voltage drop calculators want the distance between the source and destination. then internally, they double it so both the source and return wires are calculated. but you need to know which distance the calculator uses so you're not half of what you should be or double what you should be.

most circuit breakers will not take a #6 directly, so the electrician will have to splice on a smaller pigtail. you also have to upsize the grounding wire when you upsized the ungrounded (hot) wire (see note in 250.122). this will preclude using most cable assemblies, as a cable with #6 copper will most likely only have a #10 grounding conductor. you need a #6 grounding conductor if the circuit is 20a. a #8 cable is no better, as it will have a #10 grounding conductor too. but most 20a breakers will take a #8 directly.

in your related post, you didn't say what type of load this is. if it is a light or heater, voltage drop won't be a big issue. if this is a motor, the current needs are huge at startup and the voltage drop can pose a problem. if this is a motor, knowing if the motor is under much load during startup will answer the voltage drop effect (a saw is easier to start than a compressor).