Which of these describes a challenge that the engineer of a high-altitude airplane would need to consider?
A. More fuel is used at higher altitudes.
B. The airplane may succumb to the power of gravity as lift
decreases at higher altitudes.
C. The airplane may need a heat shield for protection from sonic
booms.
O D. The airplane will create more drag at higher altitudes than lower
altitudes.

Air can be considered a mixture. which statement does not explain why?

Electromagnets coils of wire paper clips picked up 10 3 15 6 20 9 25 12 ms. owens' class was studying magnets. ms. owens showed her students how to make an electromagnet using a nail, a d-cell battery, and plastic coated wire. the students wrapped the wire around the nail and then attached the ends to the battery. when they were finished, they tested their magnets by investigating how many paperclips their magnets could pick up. they also tested whether they could increase the strength of their electromagnets by using more coils of wire. they recorded the class average of their results in the data table seen here. ms. owens asked her students to graph their data in a line graph. how should the students label the x-axis on their line graph? a) size of battery b) number of paper clips c) number of coils of wire d) strength of electromagnet

What does a complete balanced chemical equation include? a. exothermic coefficients b. endothermic coefficients c. valence electrons d. molar coefficients