Question

A particle moves along the x-axis with a position given by the equation $x=5+3t$, where $x$ is in meters, and $t$ is in seconds. The positive direction is east. Which of the following statements about the particle is false?

• A. The particle is east of the origin at $t=0$
• B. The particle is at rest at $t=0$
• C. The particle's velocity is constant
• D. The particle's acceleration is constant

Answer 1

The correct option is B The particle is at rest at $t=0$

Given position vector is: $x=5+3t$

Hence, at $t=0,x=5m$ i.e., particle is east of origin. Option A is correct.

Comparing with second equation of motion,

$s=ut+\frac{1}{2}a{t}^2$

$u=3m/s$

Option B is false

$a=0$ Thus, option D is true.

Hence, particle's velocity is constant. Option C is true.