Which Equations constant I use here ?

[r-soy]

Hi ALL



which Equations constant I use here ?



a truck covers a distance of 50 m in 8 s while smoothly sowing down to a final speed of 2.5 m/s . find its original speed



Dx = 50 m

t = 8 s

v = 2.5 m/s



Now I take this equation bit I don't now why I didn't get the correct answer





Dx = (v + v0 ) t/2



=50 = 2.5 + v0 ) 8 /2

=2 X 50 + 92.5 + v0 ) 8 /2

=100 = 20 + 8v0/2

=128v

v = -128

 

[tomwilliam]

I think you've just added it up wrongly.
50m = (2.5m s^-1 + v0 ) 8s /2

is right.
Solve for v0.

 

[r-soy]

but here in my book the answe is 10 m/s

??


they do v0 = 2DX/2-v = 2 X 50 /8 -2.5 = 10

??please I want the help beacuse I fell confused

I wait