Question

A moving train is brought to rest within 20 seconds by applying brakes . Find the initial velocity if the retardation due to brake is 2 m/s

Answer 1

v=u+at here a=-2
0=u-2(20)
u=40m/s

Answer 2

ᴠ=ᴜ+ᴀᴛ ʜᴇʀᴇ ᴀ=-2
0=ᴜ-2(20)
ᴜ=40ᴍ/s