Final answer:
Doubling the mass of the pendulum does not change its natural frequency due to gravity; it remains at 7 Hz, as frequency in simple harmonic motion like a pendulum is independent of mass.
Step-by-step explanation:
The question is asking about the impact of doubling the mass on the pendulum on its frequency of oscillation. In simple harmonic motion, such as that of a pendulum, the frequency f is not dependent on the mass of the oscillating object, it depends on the length of the pendulum and the acceleration due to gravity. The formula for the frequency of a simple pendulum is f = (1/2π) * (√(g/l)), where g is the acceleration due to gravity, and l is the length of the pendulum. Since neither g nor l are changing, when the mass on the pendulum is doubled, the natural frequency remains the same. So the answer is: Doubling the mass does not affect the frequency; it remains at 7 Hz.