Answer:
Height = 7 cm
Explanation:
A block of southern pine has a mass of 54.60 g and density of 0.65 g/cm³.
The block is a rectangular prism with a length of 4 cm and a width of 3 cm.
Now we know

It is given in the question that mass = 54.60 g
and volume = 54.60 = (length×width×height)
Therefore by putting these values in the question
0.65 = 54.60/ (Length×width×height) = 54.60/(4×3×h)
12h×(0.65) = 54.60
7.80h = 54.60
h = 54.60/7.80 = 7 cm
Answer is height = 7 cm.