4. In this Question, the unit vector i is horizontal and the unit vector j is vertically upwards. All forces are in Newtons. - A small, heavy box is suspended in mid-air and is held'in equilibrium by the tension in a light inextensible string and a horizontal force, as shown in the diagram. TI j F1 LP. mg The tension in the string is T1, where T1 = 301+ 49j. The horizontal force is F1, where F1 =pl (a) Find the value of p. [1] Mathematics 9 1 of 2 20101122 MEI Education integralmalhsorg Innovation Edexcel AS Maths Force Assessment (b) Find the mass m. [1] (c) Calculate the magnitude of T1 and the angle that T1 makes with the horizontal. [3] {mother force F2 = 48i ,87j is now applied to the box. The force F] still acts and the box IS still in equilibrium. 4 (d) The new tension in the string is T2 = ai + bj. Calculate the values of a and b. [3]