12) Two identical particles of charge 6 μC and mass 4 μg areinitially at rest and held 4 cm apart. How fast will the particlesmove when they are allowed to repel and separate to very large(essentially infinite) distance? Answer: Last Answer

Hint: The particles are identical, so you can assume that thescenario is symmetrical. Use energy conservation: What type ofenergy is stored in the system when the particles are near eachother and at rest? How does the voltage of a particle allow you tocompute this energy? What about when the particles have flown awayfrom each other? What is the relationship between these energies,according to energy conservation? (Also, remember that the SI unitfor mass is the *kilo*gram and you are given the particle masses in*micro*grams.)

Now suppose that the two particles have the same charges fromthe previous problem, but their masses are different. One particlehas mass 4 μg as before, but the other one is heavier, with a massof 28 μg. Their initial separation is the same as before. How fastare the particles moving when they are very far apart? [Enter theheavier particle's final speed in the first box and the lighterparticle's final speed in the second box.]

Answer 1 of 2:

Answer 2 of 2:

Hint: Notice that the asymmetry in the particle masses meansthat you cannot assume that they end up with the same speeds afterseparating. Use momentum conservation to help solve thisproblem.