Answer:
0 m/s²
Step-by-step explanation:
Draw a free body diagram (see attached).
Sum of the forces normal to the incline:
∑F = ma
N − mg cos θ = 0
N = mg cos θ
Sum of the forces parallel to the incline:
∑F = ma
mg sin θ − f = ma
mg sin θ − Nμ = ma
Substituting:
mg sin θ − (mg cos θ) μ = ma
g sin θ − g μ cos θ = a
a = g (sin θ − μ cos θ)
Given that g = 9.8 m/s², θ = 30°, and μ = 1/√3:
a = (9.8 m/s²) (sin 30° − 1/√3 cos 30°)
a = (9.8 m/s²) (1/2 − 1/2)
a = 0 m/s²
The acceleration down the incline is 0 m/s².