A Train Traveling Slows Down Suddenly Stops After 20 Meters At -30 M/S^2, Prove That..., The Final Velocity Is 34.64 M/S , The Time It Requires To Sto
A train traveling slows down suddenly stops after 20 meters at -30 m/s^2
Prove that...
The final velocity is 34.64 m/s
The time it requires to stop is 1.16 seconds
Problem:
A train traveling slows down suddenly stops after 20 meters at -30 m/s^2
Prove that...
The final velocity is 34.64 m/s
The time it requires to stop is 1.16 seconds
Note: it is impossible to prove that final velocity is 34.64 m/s since a train suddenly stop means final velocity is 0 m/s. But it can be proven if initial velocity is 34.64 m/s.
Given:
t (time) = 1.16 seconds
d (distance) = 20 meters
a (acceleration) = -30 m/s^2 (negative since its decelerating)
Vi (initial velocity) = ? unknown to prove 34.64 m/s
Solution:
We can use the formula d = Vit + 1/2at^2
To solve for Vi, we can use Vi = d - 1/2 at^2 / t
Vi = d - 1/2 at^2 / t
= 20 m - 1/2 × (-30 m/s^2) × (1.16 s)^2 / 1.16 s
= 20 m - (- 15 m/s^2 × 1.3456 s^2 )/ 1.16 s (cancel unit s^2)
= 20 m - (- 20.184 m) / 1.16 s
= 40.184 m/ 1.16 s
= 34.64 m/s
Answer:
velocity initial is 34.64 not velocity final.
Hope it helps...=)
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