An object moving with uniform acceleration has a velocity of 11.0 cm/s in the positive x-direction when its x-coordinate is 2.82 cm. If its x-coordinate 3.55 s later is −5.00 cm, what is its acceleration?
s = vt + 1/2 at^2
so,
11*3.55 + 1/2 a * 3.55^2 = -7.82
a = -7.44 cm/s^2