Respuesta :
Answer:
a) 16.46 seconds.
b) 13.46 seconds
c) 2.67 m/s²
Explanation:
Acceleration = a = 1.35 m/s²
Final velocity = v = 80 km/h = [tex]80\frac{1000}{3600}=22.22\ m/s[/tex]
Initial velocity = u = 0
Equation of motion
[tex]v=u+at\\\Rightarrow 22.22=0+1.35t\\\Rightarrow t=\frac{22.22}{1.35}=16.46\ s[/tex]
Time taken to accelerate to top speed is 16.46 seconds.
Acceleration = a = -1.65 m/s²
Initial velocity = u = 80 km/h= [tex]80\frac{1000}{3600}=22.22\ m/s[/tex]
Final velocity = v = 0
[tex]v=u+at\\\Rightarrow 0=22.22-1.65t\\\Rightarrow t=\frac{22.22}{1.65}=13.46\ s[/tex]
Time taken to stop the train from top speed is 13.46 seconds
Initial velocity = u = 80 km/h= [tex]80\frac{1000}{3600}=22.22\ m/s[/tex]
Time taken = t = 8.3 s
Final velocity = v = 0
[tex]v=u+at\\\Rightarrow 0=22.22+a8.3\\\Rightarrow a=\frac{-22.22}{8.3}=-2.67\ m/s^2[/tex]
Emergency deceleration is 2.67 m/s²
