Answer:
0.84
Explanation:
First, convert km/h to m/s.
62 km/h × (1000 m / km) × (1 h / 3600 s) = 17.2 m/s
Next, find the acceleration.
v² = v₀² + 2aΔx
(0 m/s)² = (17.2 m/s)² + 2a (18 m)
a = -8.24 m/s²
Now, find the friction force.
∑F = ma
-F = (1500 kg) (-8.24 m/s²)
F = 12,400 N
On a level surface, normal force equals the weight.
N = mg
N = (1500 kg) (9.8 m/s²)
N = 14,700 N
The coefficient of kinetic friction is therefore:
μ = F / N
μ = 12,400 N / 14,700 N
μ = 0.841
Rounding to two significant figures, the coefficient of kinetic friction is 0.84.
