Question

Work done by an individual force is zero if the work done by the resultant force is also zero

• A. True
• B. False

Answer 1

The correct option is B False

Let $F_1,F_2......F_n$ be n non zero force vectors.

Work done by the forces=$(F_1+F_2.......+F_n).d=F_1.d+F_2.d+......F_n.d$

Now in the equation

LHS can ne zero when the vector sum of all forces =0,

But RHS(individual work done) needn't be zero.

For example,

Suppose two forces be 2i, -2i,

And displacement be 3i,

Then

Total work done=(-2i+2i).3i=0$

Individual work done,

$W_{2i}=6J$

$W_{2i}=-6J$

Hence the statement is false.