Final answer:
The weight of the pine wood block is 800 grams.
Step-by-step explanation:
To calculate the weight of the pine wood block, we need to determine its volume and then multiply it by its density. The volume of the block can be calculated by multiplying its length, width, and thickness. Given that the block is 10.0 cm x 40.0 cm x 5.0 cm, the volume is (10.0 cm) x (40.0 cm) x (5.0 cm) = 2000 cm³.
The density of the block is given as 0.40 g/cm³. To calculate the weight, we can use the formula weight = volume x density. So, weight = (2000 cm³) x (0.40 g/cm³) = 800 g.
Therefore, the weight of the pine wood block is 800 grams.