Answer:
A. 420 J
Explanation:
Given the following data;
Mass = 30.45 g
Specific heat capacity = 4.18 J/g °C.
Temperature = 3.3°C
To find the quantity of heat;
Heat capacity is given by the formula;
Where;
Q represents the heat capacity or quantity of heat.
m represents the mass of an object.
c represents the specific heat capacity of water.
t represents the temperature.
Substituting into the equation, we have;
Q = 420.03 ≈ 420 Joules
Answer:
2.85 rad/s
Explanation:
5 cm = 0.05 m
20 g = 0.02 kg
When dropping the 2nd object at a distance of 0.05 m from the center of mass, its corrected moments of inertia is:

So the total moment of inertia of the system of 2 objects after the drop is:

From here we can apply the law of angular momentum conservation to calculate the post angular speed

The answer would be to research the need. This should have been done before the project began.
B. Ptolemy believed that the earth was the center of the universe