Stating and Testing a Theory — practice questions

State the two things a conclusion must contain for this standard at Achieved level.

A student's conclusion reads: "My experimental value of $g$ was $9.5$ m s⁻², which is close to the accepted value of $9.81$ m s⁻², so the theory is supported."

Explain why this does not meet the Merit criterion, and rewrite it so that it does. The student's gradient analysis gave $g = 9.5 \pm 0.4$ m s⁻².

A student obtains $g = 9.5 \pm 0.1$ m s⁻² from their pendulum investigation. The accepted value is $9.81$ m s⁻².

Discuss what this result means, and what it tells the student about their investigation.

Theory predicts that the energy stored in a spring $E$ depends on its extension $x$ as $E = \tfrac{1}{2}kx^2$. State the power $n$ this predicts for a log-log plot of $E$ against $x$.

Explain why stating the predicted power $n$ before collecting data is better practice than only working it out afterwards.

An investigation into $T = 2\pi\sqrt{L/g}$ finds a log-log gradient of $0.52 \pm 0.04$ and an experimental $g$ of $9.6 \pm 0.5$ m s⁻². Evaluate whether this data supports the theory.