Answer:
13 N
Step-by-step explanation:
From the question,
(F₁+F₂)-F' = ma................ Equation 1
Where F₁= Jack's force, F₂ = Jill's force, F' = Friction force, m = mass of the object, a = acceleration of the object.
Given: F₂ = 4 N, F' = 2 N, m = 3 kg, a = 5 m/s²
Substitute these values into equation 1 and solve for F₁
(F₁+4)-2 = 3×5
(F₁+4)-2 = 15
F₁+4 = 15+2
F₁+4 = 17
F₁ = 17-4
F₁ = 13 N
Hence the force applied by Jack is 13 N