A train starts from rest. It moves through 1 Km in 100 s with uniform acceleration.
What will be its speed at the end of 100 s.
Answers
Given :
Initial velocity, u = 0 m/s (as it is starts from rest)
Distance, s = 1 km = 1000 m
Time, t = 100 seconds
To find :
Speed, v
According to the question,
➞ s = ut + ½ at²
Where,
s = Distance
a = Acceleration
t = Time
u = Initial velocity
➞ 1000 = 0 × ½ 100 + a × 100 × 100
➞ 1000 = 0 + 5000a
➞ 1000 - 0 = 5000a
➞ 1000 = 5000a
➞ 1000 ÷ 5000 = a
➞ 0.2 = a
So,the acceleration is 0.2 m/s².
Now,
➞ v = u + at
Where,
v = Final velocity
u = Initial velocity
a = Acceleration
t = Time
➞ v = 0 + 0.2 × 100
➞ v = 0 + 20
➞ v = 20
So,the speed is 20 m/s.
First using 2nd equation of motion -
Now we need to find the final velocity ‘v’ as asked in the question
So by using 1st equation of motion, We get :-
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━