when the mass of the cylinder increased from 3.0 kg to 6.0 kg, what happened to the amount of heat generated…

Explanation:

Step1: Recall heat - mass relation

The heat generated $Q = mc\Delta T$ (where $m$ is mass, $c$ is specific heat capacity and $\Delta T$ is change in temperature). Assuming $c$ and $\Delta T$ are constant, $Q$ is directly proportional to $m$.

Step2: Analyze mass change

The initial mass $m_1 = 3.0$ kg and the final mass $m_2=6.0$ kg. The ratio of the final mass to the initial mass is $\frac{m_2}{m_1}=\frac{6.0}{3.0}=2$. Since $Q\propto m$, when the mass doubles, the heat generated also doubles.

Answer:

It increased by a factor of 2.