Answer:
Step-by-step explanation:
The stored elastic energy in the spring helps the box to rise to a height of .75 m
So stored elastic energy = potential energy attained
1/2 k d² = mgh , k is spring constant , d is compression in spring , m is mass of box , h is height attained .
Putting the values
.5 x 220 x d² = 4 x 9.8 x .75
d² = .2673
d = .517 m
51.7 cm .