A pendulum clock is taken from sea level to a high-altitude location where the acceleration due to gravity is 9.7 m/s². At sea level, the clock kept perfect time. At the high-altitude location, the clock will:

Core Concept

The period of a pendulum is T = 2π√(L/g). As g decreases (from approximately 9.8 m/s² at sea level to 9.7 m/s² at high altitude), the period increases. Since the pendulum takes longer to complete each swing, the clock will run slow.