Questions: (d) Calculate the mass M of the metre ruler using the equation M = k / (G-1), where k = 25 g. Give an appropriate unit. M = (e) The accuracy of the result obtained by this procedure depends on the metre ruler, without a load, balancing with the pivot at the 50.0 cm mark. A student finds that this does not happen. She adds a small piece of modelling clay to one end of the metre ruler to correct it. Suggest if this is a suitable change for this experiment. Explain your answer.

Solution Steps

We are given the equation for the mass \( M \) of the metre ruler: \[ M = \frac{k}{(G-1)} \] where \( k = 25 \, \text{g} \).

The variable \( G \) is not explicitly given in the problem statement. For the purpose of this calculation, we assume \( G \) is a known value greater than 1.

Substitute \( k = 25 \, \text{g} \) into the equation: \[ M = \frac{25 \, \text{g}}{(G-1)} \]

The equation is already in its simplest form: \[ M = \frac{25 \, \text{g}}{(G-1)} \]

\[ \boxed{M = \frac{25 \, \text{g}}{(G-1)}} \]

Adding a small piece of modelling clay to one end of the metre ruler to correct its balance is a suitable change for this experiment. This adjustment ensures that the metre ruler balances at the 50.0 cm mark without any load, which is crucial for the accuracy of the measurements. By doing so, the centre of mass of the ruler is correctly positioned, allowing for more precise experimental results.

Final Answer