A train slows from a speed of 40 m/sec to a speed of 30 m/sec in 1500 m. What is its acceleration?

I tried to solve this but I can't get the right formula >.<

RainbowPanda
Sep 20, 2018

#1**+1 **

I'm not a Physics expert, but I believe we need this equation, RP

VF^2 =VI^2 + 2 * a * d

VF = 30m/s

VI = 40m/s

d = the displacement [ how far it moves]....so we have

a = acceleration (in m/s^2) = ???

30^2 = 40^2 + 2 * a (1500)

900 = 1600 + 3000a subtract 1600 from both sides

-700 = 3000a divide both sides by 3000

-700 / 3000 = a = -7/30 m/s^2 ≈ -0.233 m/s^2 [ this makes sense....we are decelerating !!! ]

CPhill
Sep 20, 2018