Maria and miquel were enjoying the fireworks when they got into a chemistry argument. maria insisted that the fireworks were the result of a chemical reaction. miguel disagreed. what would you tell them to solve this argument.

a)
it is a change of state, solid to gas, due to the addition of energy.

b)
it was a physical reaction since the fuse was lit and heat was produced.

c)
the color changes and the release of energy indicate a chemical reaction.

d)
it is an endothermic reaction because energy was added; therefore it is a chemical reaction,

Consider a double atwood machine constructed as follows: a mass 4m is suspended from a string that passes over a massless pulley on frictionless bearings. the other end of this string supports a second similar pulley, over which passes a second string supporting a mass of 3m at one end and m at the other. using two suitable generalized coordinates, set up the lagrangian and use the lagrange equations to find the acceleration of the mass 4m when the system is released. explain why the top pulley rotates even though it carries equal weights on each side.