The initial velocity of a motor cycle is 5 m/s. After 3 seconds, the velocity becomes 7 m/s. The displacement of the motor cycle in 3 seconds will be :

Using the equation of motion s = ((u + v)/2) × t for uniformly accelerated motion: s = ((5 + 7)/2) × 3 = (12/2) × 3 = 6 × 3 = 18 m. Alternatively, acceleration a = (v−u)/t = (7−5)/3 = 2/3 m/s², and s = ut + ½at² = 5×3 + ½ × (2/3) × 9 = 15 + 3 = 18 m. Hence the displacement is 18 m.