A block of mass 3 kg is hung from a spring,

Question

causing it to stretch 21 cm at equilibrium, as
shown below.
The 3 kg block is then replaced by a 4 kg
block, and the new block is released from
the position shown below, at which point the
spring is unstretched.
21 cm
ymax
3 kg
equilbrium
4 kg
How far will the 4 kg block fall before its
direction is reversed? For the new block case,
the total distance of fall is twice the amplitude
of the oscillation. The acceleration due to
gravity is 9.8 m/s
2
.
Answer in units of cm