Answer: A
0.485 Kg
Explanation:
Since the iron weight is motionless, the magnitude of tension T in the string will be equal but opposite to the magnitude of the weight W.
T = W
Where W = mg
T = mg
Where T = 4.75 N, g = 9.81m/s^2
4.75 = 9.81m
m = 4.75/9.81
m = 0.485 Kg
Therefore, the mass of the iron weight is approximately 0.485 kg
