A submarine must travel how fast (with respect to the water) and ...

[Chloeellawright]

A submarine must travel how fast (with respect to the water) and be pointed in what direction such that it moves 10. m/s directly Northward (relative to the Earth) if the water moves westward at 5.0 m/s?
 
  What will be an ideal response?

Question 2

Why does the Sun brighten with time?
 
  A) as time progresses, helium starts to fuse in the core, in addition to hydrogen, leading to an increase in brightness
  B) as hydrogen is converted into helium in the core, the number of hydrogen nuclei decreases, decreasing the fusion rate. To maintain the balance with gravity pressing inward, the core compensates by shrinking and heating up
  C) as time progresses, more and more heat is trapped inside the core, leading to an increase in brightness
  D) as hydrogen is converted into helium in the core, the number of hydrogen nuclei decreases, decreasing the fusion rate. To maintain the balance with gravity pressing inward, the core compensates by expanding and cooling

[cloud]

Answer to Question 1

11. m/s at 63 N of E

Answer to Question 2

B

[Chloeellawright]

Excellent

[ghepp]

Gracias!