Final answer:
To calculate the period of a simple pendulum, use the formula T = 2π√(L/g), which yields approximately 1.29 seconds for a pendulum with a length of 42 cm.
Step-by-step explanation:
The question involves calculating the period of oscillation for a simple pendulum. The formula for the period T of a simple pendulum is T = 2π√(L/g), where L is the length of the string and g is the acceleration due to gravity, which is approximately 9.81 m/s². Plugging the given length of the string, 0.42 meters, into the formula gives us T = 2π√(0.42/9.81), which calculates to approximately 1.29 seconds for the period of oscillation.