Four objects are distributed aver a meter plank, which is pivoted at its center of gravity, as follows: a 2.0 kg object is at 13.0 cm mark, a 3.0 kg object is at 12.5 cm mark, a 2.5 kg object is at the pivot and another object is at 87.3 cm mark. Calculate: a) The mass of object which is at 87.3 cm mark. 3kg 2kg 2.5kg 37.00 cm 37.50 cm Pivot 37.30 cm M4 b) Reaction force at the pivot.