the resultant of two forces 3N and 4N making an angle 90 with each other is
a) 1N b) 7N c) 5N d) 3.5N

Question

the resultant of two forces 3N and 4N making an angle 90 with each other is
a) 1N b) 7N c) 5N d) 3.5N

anonymous · Answer

the answer would be 5N
apply this formula for resultant
 
$$\sqrt{A ^{2}+B ^{2}+2AB \cos \theta}$$
cos90=0
so,
$$\sqrt{4^{2}+3^{2}}=\sqrt{16+9}=\sqrt{25}=5$$

anonymous · Answer

is it correct equation?

anonymous · Answer

they are at 90 degree with each other. why is not sin theta in place of cos theta?

anonymous · Answer

i am not quite sure about answer!you can ask someone who is confirmed about it.

anonymous · Answer

you can take it as forula,if you ever want to calculate the resultant of two vectors,this formula is used