Answer:
-0.75 m
Explanation:
The displacement of the girl is given by x = x₀cosωt where x₀ = maximum displacement of swing = 1.5 m, ω = angular frequency = π/3 rad/s and t = time of swing = 4 s
Substituting the values of the variables into the equation, we have
x = x₀cosωt
x = (1.5 m)cos(π/3 rad/s × 4 s)
x = (1.5 m)cos(2π/3)
x = (1.5 m)cos120°
x = 1.5 m × -0.5
x = -0.75 m
So, the girl is 0.75 m to the left of the equilibrium position 4 seconds into the motion.