Question

A particle moves according to the equation $x=a\cos \left(\pi t/2\right)$. The distance covered by it in the time interval between $t=0$ to $t=3$ s is

• A. 2a
• B. 3a
• C. 4a
• D. a

Answer 1

Answer: (B)

3a

At $t=0;$
$x=a$
At $t=3$ ;
$x=acos$ $\left(\frac{3\pi }{2}\right)=0$
The particle moves from one extreme to the other extreme and then to mean.
Thus $3a$.