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

Answer 1

the answer would be 5N
apply this formula for resultant

\[\sqrt{A ^{2}+B ^{2}+2AB \cos \theta}\]
cos90=0
so,
\[\sqrt{4^{2}+3^{2}}=\sqrt{16+9}=\sqrt{25}=5\]

Answer 2

is it correct equation?

Answer 3

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

Answer 4

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

Answer 5

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