3. X and Y are two objects on a frictionless table connected by a string. The mass of X is 2kg and the mass of Y is 4 kg. The mass of the string is negligible. A constant horizontal force of 12N acts on Y. 6kg 12 N X string Y 12 N 2 kg 4 kg What are the acceleration of Y and the magnitude of the tension in the string? Acceleration of Y/ms 2 Tension in the string/N A. 4 B. 2 6 C. 3 4 D. 6