Initial velocity of the object, u = 5 m/s

Final velocity of the object, v = 8 m/s

Mass of the object, m = 100 kg

Time take by the object to accelerate, t = 6 s

Initial momentum = mu = 100 × 5 = 500 kg ms^{-1 }

Final momentum = mv= 100 × 8 = 800 kg ms ^{-1}

Force exerted on the object, F = mv - mu / t

Initial momentum of the object is 500 kg ms^{-1} .

Final momentum of the object is 800 kg ms ^{-1} .

Force exerted on the object is 50 N.