1. If a density of a certain kind of wood is 0.5 cm3 what is the mass of : a. 1cm3
b. 2 cm3
c. 10 cm3

2. A clear plastic box has a base of 6 cm sq and contains water to a height of 7 cm. what is the volume of the water in the box? A stone is lowered into the water so that it is completely covered. The water rises to a height of 9 cm. What is the volume of the stone?
( with working please )

All the simple machines make work easier to do by changing the or of a force. a. size; type b. work; type c. size; direction d. type; direction

If gases like carbon dioxide and methane make up less than 1% of the total atmosphere, why is it important for scientists to monitor changes in percentages of these gases?

30 points - when can a theory be modified if a new type of technology allows for new observations that raise new questions? a. immediately, while the questions about the theory are being asked b. after new hypotheses related to the theory are tested in experiments c. only after the new observations disprove all parts of the theory d. while scientists begin to think about how the theory could improve