Final answer:
The period of the block's oscillation, which is the time it takes to complete one cycle, is calculated by dividing the total time by the number of cycles, resulting in a period of 0.5 seconds.
Step-by-step explanation:
The period of oscillation of an object is defined as the time it takes to complete one full cycle of motion. In the given problem, a 100-g block completes 20 cycles in 10 seconds. To find the period, we would divide the total time by the number of cycles:
Period = Total Time / Number of Cycles
Period = 10 s / 20 cycles
Period = 0.5 s
Therefore, the period of the block's oscillation is 0.5 seconds.