A particle moving with velocity V is acted by three forces shown by the vector triangle PQR.

Question

A particle moving with velocity $\vec{V}$ is acted by three forces shown by the vector triangle PQR. The velocity of the particle will :

(1) increase

(2) decrease

(3) remain constant

(4) change according to the smallest force $\overrightarrow{QR}$

Answer 1

Ans: (3) remain constant

Sol: Since vector sum of forces formed a closed polygon, therefore net force on the particle is zero i.e. acceleration= 0. Hence, velocity of particle remains unchanged.