Question

A mass m = 100 gms is attached at the end of a light spring which oscillates on a friction less horizontal table with an amplitude equal to 0.16 meter and the time period equal to 2 sec. Initially the mass is released from rest at t = 0 and displacement x = – 0.16 meter. The expression for the

displacement of the mass at any time (t) is

• A. $x = 0.16\cos(\pi t)$
• B. $x = - 0.16\cos(\pi t)$
• C. $x = 0.16\cos(\pi t + \pi)$
• D. $x = - 0.16\cos(\pi t + \pi)$

Answer 1

Answer: (B)

$x = - 0.16\cos(\pi t)$

Answer 2

Standard equation for given condition

$x = a\cos\frac{2\pi}{T}t$ ⇒ $x = - 0.16\cos(\pi t)$

[As a = – 0.16 meter, T = 2 sec]