User:Raphealpusparaj/sandbox

Aim
To verify the law of parallelogram of forces.

Apparatus required
Vertical board, two pulleys, Slotted weights, mirror, string clips,

Statement
If two forces acting at a point can be represented both in magnitude and direction by the two adjacent sides of a parallelogram then their resultant can be represented both in magnitude and direction by the diagonal passing through that point.

Procedure
Fix a sheet of paper to the vertical board. Fix two pulleys on the top edge of the board. Take three strings - one end of which is tied together to form a common knot. Pass to strings over the two pulleys and suspend three slotted weights P, Q and R from the free ends of three strings. Adjust the weights in order to keep the knot in equilibrium. . Mark the lines of force on the paper using plane mirror by avoiding parallax. Using a convenient scale, mark OA, OB, OC, proportional to P, Q and R respectively. Complete the parallelogram OADB. Join O and D. Measure OD and angle COD. Repeat the same procedure for different sets of forces.

Result
Within the experimental errors one should verify OD=OC and angle COD =180°