Question

two forces equal to p and 2p newton acts on a particle. if the first be doubled and second is increased by 20 newton, the direction of the resultant is unaltered. Find the value of p

Answer 1

The two triangles formed by the vectors and their resultants in the two cases will be similar BECAUSEdirection of resultant is unaltered. Thus

(2P +20) :2P= 2 :1 [As the first vector is doubled]

= P= 10 N

Answer 2

The value of p is 5N

SOLUTION:

For the 1st case of the given force

p and 2 p are the forces acting on a particle

So now for 2nd case the first force is doubled and the second one is increased by 20 N.

2 p and 2 p+20 are the forces acting on a particle

As the direction is unaltered ...it implies forces must have act in opposite directions and they will b equal in magnitude

So 2 p= -2 p+20. [- sign for opposite direction]

4 p=20

$p=\frac{20}{4}$

p=5 N.