Question

a ship is moving at a speed of 56km/hr. One second later , it is moving at a speed of 58km/hr. what is its acceleration

Answer 1

u = 56 km/h = (56*5)/18 m/s = 15.55 m/s
v = 58 km/h = (58*5)/18 m/s = 16.11 m/s
time, t = 1s

acceleration = (v-u)/t = (16.11-15.55)/1 = 0.55 m/s²

Answer 2

initial velocity = u = 56 kmph
v = final velocity = 58 kmph

change in velocity = v - u = 2 kmph = 2 * 5/18 = 5/9 m/sec
time duration t = 1 second.

acceleration = a = (v - u) / t = 5/9    m/sec²    =  0.5556  m/sec²