Answer:
The speed of the last car is 21.18 m/s.
Explanation:
Given that,
Length of train = 75 m
Speed of train= 18 m/s
Distance 195 m
Suppose the acceleration is constant.
We need to calculate the speed of the last car
Using equation of motion
[tex]v^2=u^2+2as[/tex]
[tex]a=\dfrac{v^2-u^2}{2s}[/tex]
For train and car,
[tex]\dfrac{v^2-u^2}{2s}=\dfrac{v'^2-u'^2}{2s'}[/tex]
Where, v = final velocity of train
u = initial velocity
s = distance
u'= speed of train
s'=distance
Put the value into the formula
[tex]\dfrac{18^2-0}{2\times195}=\dfrac{v'^2-18^2}{2\times75}[/tex]
[tex]v'^2=\dfrac{18^2\times2\times75}{2\times195}+18^2[/tex]
[tex]v'=\sqrt{448.61}[/tex]
[tex]v'=21.18\ m/s[/tex]
Hence, The speed of the last car is 21.18 m/s.
