A boy moving with a velocity of 3m/s is brought to rest by a constant force after traveling 15m. Calculate the retardation

Physics Jamb, Waec, Neco Past Questions & Answers on Speed, Velocity and Acceleration

QUESTIONS 16. A boy moving with a velocity of 3m/s is brought to rest by a constant force after traveling 15m. Calculate the retardation 

NECO 2000 Ans: 0.3m/s²

SOLUTIONS

Initial Velocity u = 3m/s

Final velocity v = 0 m/s

Distance s = 15m 

Retardation (negative of acceleration) = acceleration = a = or -a = ?

Applying the third equation of motion

V² = u² + 2as

0² = 3² + 2(a)(15)

0 = 9 + 30a

0-9 = 30a

-9/30 = -a

Therefore -a = -0.3m/s²

a = 0.3m/s²