Final answer:
The ball passes through the lowest point of its arc 4 times in 9.8 seconds.
Step-by-step explanation:
The number of times the ball passes through the lowest point of the arc in 9.8 seconds can be determined using the formula for the period of a pendulum. The period, T, of a pendulum, is given by the formula T = 2π√(L/g), where L is the length of the string and g is the acceleration due to gravity. In this case, L = 130 cm = 1.3 m and g = 9.8 m/s². First, calculate the period using the given values:
T = 2π√(1.3/9.8)
T = 2π x 0.36
T = 2.26 seconds
Next, calculate the number of periods in 9.8 seconds:
Number of periods = 9.8 / 2.26 = 4.33
Rounding to the nearest whole number, the ball passes through the lowest point of its arc 4 times in 9.8 seconds.