Answer:
g = 12.22 m/s²
Step-by-step explanation:
The time period of this pendulum is given as follows:

but the formula for the time period of a simple pendulum is as follows:

where,
L = length of pednulum = 48 cm = 0.48 m
g = magnitude of th gravitational acceleration on this planet = ?
Therefore,

g = 12.22 m/s²