Question

27
Three forces acting on a body are shown in the
fiqure. To have the resultant force only alono the
y-direction, the magnitude of the minimum
additonal force needed is (AIPMT (Prelims)-2008
UN

(1) root3N
(2) O.5N
(3) 1.5 N
(4) root 3/4​

Answer 1

The answer is (2)0.5N (towards x- axis )

It can be explained as:-

Consider the figure in attachment,

For motion only along y-axis,

x+2Nsin30°+1Ncos60° = 4Nsin30°

where x is additional force,

=>x +2×½+½ = 4×½

=>x+1+½ = 2

=>x+3/2 = 2

=>x = 1/2 = 0.5N

(ps:- since it is not mentioned that the question is talking about which y-axis that's negative or positive, so the answer is also anonymous of direction)

Cheers!