A horizontal tray of mass is attached to two stiff springs

PHYSICS · Single correct · A Level · Physics · Further mechanics and thermal physics · Further mechanics and thermal physics

Problem

A horizontal tray of mass

150\,\text{g}

is attached to two stiff springs. With only the tray oscillating, its period of small horizontal vibrations is

0.60\,\text{s}

. When an additional standard mass of

450\,\text{g}

is clamped on the tray, the period becomes

1.20\,\text{s}

. An unknown sample is now placed on the tray (in addition to the tray itself) and the period is observed to be

0.90\,\text{s}

. Neglecting friction, find the mass of the unknown sample. (a)

0.34\,\text{kg}

(b)

0.23\,\text{kg}

(c)

0.19\,\text{kg}

(d)

0.09\,\text{kg}