posted by Tom .
A train traveling at a speed of 110 km/h uniformly decelerates for 20 seconds. During that time it travels 450 m.
a. What is the acceleration ? = m/s2
b. What is its speed after the deceleration ? = km/h
s = v0*t + 1/2 at^2
plug in your numbers for v0 (convert to m/s) and t.
now, use that value of a for
v = v0 + at
and then convert m/s to km/hr