Use the conservation of angular momentum; angular momentum at the beginning = angular momentum at the end
Conservation of angular momentum:
I1 w1 = I2 w2
Where I is the moment of inertia. For a sphere, I=2/5 m R^2. Substituting into the equation above we get
w2 = I1 w1 / I2 = w1 m1 R1^2 / (m2 R2^2)
w2 = w1 4 * (R1/R2)^2
= 4*(1)*(7E5/7.5)^2
= 3.48E10 revs/(17days)
= 2.04705882 x 10^9 revs/sec
No se porque?
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Answer:
46.9 C
Explanation:
The heat released by the gold bar is equal to the heat absorbed by the water:

where:
is the mass of the gold bar
is the specific heat of gold
is the initial temperature of the gold bar
is the mass of the water
is the specific heat of water
is the initial temperature of the water
is the final temperature of both gold and water at equilibrium
We can re-arrange the formula and solve for T_f, so we find:

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