A passenger bus is travelling 28.0 m/s to the right when the driver applies the brakes. The bus stops in 5.00 s. What is the acceleration of the bus as it comes to a stop?

Change in velocity = d (v)

d (v) = v2 - v1 where v1 = initial speed, v2 = final speed

v1 = 28.0 m/s to the right

v2 = 0.00 m/s

d (v) = (0 - 28) m/s = - 28 m/s to the right

Change in time = d (t)

d (t) = t2 - t1 where t1 = initial elapsed time, t2 = final elapsed time

t1 = 0.00 s

t2 = 5.00 s

d (t) = (5.00 - 0.00) s = 5.00s

Average acceleration = d (v) / d (t)

(-28.0 m/s) / (5.00 s)

(-28.0 m) / s * 1 / (5.00 s) = - 5.60 m/s² to the right