Answer:
x = 1.43 cm
Step-by-step explanation:
The horizontal displacement of the pendulum can be found using the following equation:

Where:
x₀: is the initial horizontal displacement = 10 cm
ω: is the angular frequency
t: is the time = 5 s
Φ: is the phase shift = 20° = 20*2π/360 = 0.35 rad
The angular frequency can be calculated using the oscillation perid (T):
The horizontal displacement is:
Therefore, the displacement of the pendulum at 5 s is 1.43 cm.
I hope it helps you!