A mass hangs from a light spring of force constant fixed to the ceiling

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

Problem

0.50\,\text{kg}

mass hangs from a light spring of force constant

20\,\text{N/m}

fixed to the ceiling. With the spring initially at its natural length, the mass is pulled downward so the spring stretches an additional

0.30\,\text{m}

. At that instant the mass is given a downward speed of

1.0\,\text{m/s}

. What is the speed of the mass when the spring is stretched only

0.10\,\text{m}

beyond its natural length? (Assume the downward direction is positive and neglect air resistance.) (a)

1.9\,\text{m/s}

(b)

3.5\,\text{m/s}

(c)

2.8\,\text{m/s}

(d)

0.53\,\text{m/s}