Answer:
F = 7.2N
Step-by-step explanation:
The resultant of two forces acting at some angle is given by using the vector addition as given below
F =√F1^2+F2^2+2F1F2cosθ
Where F1 = 6N and F2 = 8N
θ = 240°
Substituting the values into the equation above
F = √ 6^2+8^2+ 2(6×8)cos240
F =√ 36+64+96cos240
F = √ 100+96 ×-0.5
F = √ 100-48
F = √ 52
F = 7.211
F = 7.2N