I disagree.
Many substances show fluorescence under ULTRAVIOLET light, NOT microwaves. :)
Answer:
length = 2L, mass = M/2, and maximum angular displacement = 1 degree
Explanation:
We consider only small amplitude oscillations (like in this case), so that the angle θ is always small enough. Under these conditions recall that the equation of motion of the pendulum is:

And its solution is:

Where
are the angular frequency of the oscillations, from which we determine their period:

Therefore the period of a pendulum will only depend on its length, not on its mass or angle, for angles small enough. So, the answer is the one with the greater length.
A) 1153 N/m
We can find the spring constant by using Hooke's law:

where
F is the force applied to the spring
k is the spring constant
x is the displacement of the spring
In this problem, a fish of mass m = 4.0 kg is hanging on the spring, so the force applied is the weight of the fish:

and the displacement of the spring is:

so, the spring constant is

B) 16.8 cm
In this case, a fish of mass
m = 8.0 kg
is hanging on the spring. Therefore, the force applied to the spring is

So we can find the displacement of the spring:

And since the equilibrium length of the spring is

the new length of the spring will be

Answer:
See below explanation
Explanation:
The correspondent chemical reaction for copper carbonate decomposed by heat is:
CuCO₃ (s) → CuO (s) + CO₂ (g)
Considering all molar mass (MM) for each element ( we consider rounded numbers) :
MM CuCO₃ = 123 g/mol
MM CuO = 79 g/mol
MM CO₂ = 44 g/mol
Statement mentions that scientis heated 123.6 g of CuCO₃ (almost a MM), until a black residue is obtained, which weights 79.6 g : this solid residue is formed by CuO, and the remaining mass (approximatelly 44 g) belongs to teh second product, this is, CO₂; as it is a gas compund, it is not certainly included on the solid residue.
So, law of conservation mass is true for this case, since: 123.6 g = 79.6 g + 44 g. As explained, on the solid residue, we don not include the 44 g, which "escaped" from our system, since it is a gas compound (CO₂)