Answer:
226.45 s.
Explanation:
Using Newton's fundamental equation,
F = ma.............. Equation 1
Where F = force, m = mass of the freight train, a = acceleration of the freight train.
make a the subject of the equation,
a = F/m.............. Equation 2
Given: F = 8.1×10⁵ N, m = 1.1×10⁷ kg
Substitute into equation 2
a = 8.1×10⁵/1.1×10⁷
a = 0.0736 m/s²
Using
a =(v-u)/t.................. Equation 3
make t the subject of the equation
t = (v-u)/a............... Equation 4
Given: v = 60 km/h = 60(1000/3600) = 16.67 m/s, u = 0 m/s (from rest), a = 0.0736 m/s²
Substitute into equation 4
t = (16.67-0)/0.0736
t = 16.67/0.0736
t = 226.45 s.
