Two forces of magnitude 100N and 70N act on an object . The angle between the forces is 120 degrees. What is the resultant force.

This is what I got
. ΙU ⃗+V ⃗Ι^2 = ΙU ⃗Ι+ΙV ⃗Ι-2 ΙU ⃗Ι ΙV ⃗Ι cos⁡〖60°〗
= (100)^2+(10)^2-2(100)(10)cos⁡〖60°〗
ΙU ⃗+V ⃗Ι = √7900
= 88.88

sin⁡a/(ΙV ⃗Ι)=sin⁡〖(60°)〗/(ΙU ⃗+V ⃗Ι)
sin⁡a/70=sin⁡〖(60°)〗/88.8
a = sin^(-1)⁡〖[(70sin⁡(60°))/88.88]〗
a≅43°

∴ The magnitude is 88.88N with a direction of E43°N
can anyone confirm ? :/

Question

Two forces of magnitude 100N and 70N act on an object . The angle between the forces is 120 degrees. What is the resultant force.

This is what I got 
. ΙU ⃗+V ⃗Ι^2 = ΙU ⃗Ι+ΙV ⃗Ι-2 ΙU ⃗Ι ΙV ⃗Ι cos⁡〖60°〗
  	           = (100)^2+(10)^2-2(100)(10)cos⁡〖60°〗
       ΙU ⃗+V ⃗Ι   = √7900 
                        = 88.88

sin⁡a/(ΙV ⃗Ι)=sin⁡〖(60°)〗/(ΙU ⃗+V ⃗Ι)  
      sin⁡a/70=sin⁡〖(60°)〗/88.8
         a     = sin^(-1)⁡〖[(70sin⁡(60°))/88.88]〗            
                 a≅43°

∴ The magnitude is 88.88N with a direction of E43°N
 can anyone confirm ? :/

anonymous · Answer

My answer is the resultant force is 88.88 N at an angle of 43 degrees from the 100 N force.

anonymous · Answer

oh ok so is the vector direction right E43N?

anonymous · Answer

yeah, i think so

anonymous · Answer

k thanks