How Far Does a Slowing Train Travel?

AI Thread Summary
A train decelerates from 30 m/s to 10 m/s over 30 seconds, and the problem requires calculating the distance traveled before its speed decreases from 30 m/s to 20 m/s. The relevant kinematic equations are discussed, particularly Vf² = Vi² + 2*a*x, where acceleration can be derived from the change in velocity over time. The change in velocity (ΔV) is calculated as -20 m/s, indicating deceleration. The solution involves determining the acceleration and then using it to find the distance traveled during the specified speed reduction. The discussion emphasizes the importance of understanding initial velocity and acceleration in solving the problem.
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Homework Statement



1. A train moving at a speed of 30 m/s slows down to 10m/s in 30s. How far had the train gone before it's speed was reduced from 30m/s to 20 m/s?

Homework Equations



D= Vi times T + at(squared) divide it by 2

The Attempt at a Solution


None yet. Please help me with the solution
 
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Honestly I am having a hard time figuring out what the initial velocity is.. and the acceleration
 
You can figure the "a" simply by using the relationship that ΔV = a*t That Δ v is (10 - 30) = -20 = a*t

Using the V2 = ... formula then your final speed is 10 m/s and you Initial is 30 and your acceleration is negative because it's slowing you down to 20, then you can figure x.
 

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