2019 Laws of MotionNewton's First Law – Equilibrium of Concurrent Forces Medium Question 23 of 72 in Laws of Motion

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

A increase
B decrease
C remain constant
D change according to the smallest force $\overrightarrow{QR}$

The answer is C.

Solution

The three forces form a closed triangle taken in the same order, so $\vec{F}_{net}=0$.
$m\frac{d\vec{v}}{dt}=0\Rightarrow\vec{v}=$ constant
So the velocity of the particle remains constant.

Concept particle under a closed triangle of forces

Laws of Motion in past papers

72 questions from this chapter have appeared across 27 exam years.