The correct situation describing opposite quantities combining to equal 0 is when a family rides their bikes four miles east and then four miles west, resulting in no net displacement. So, the correct option is (2)
The situation that describes opposite quantities which when combined would equal 0 is:
A family rides their bikes four miles due east from home. Then, they ride their bikes four miles due south. How far is the family from home?
A family rides their bikes four miles due east from home. Then, they ride their bikes four miles due west. How far is the family from home?
A family rides their bikes four miles due north from home. Then, they ride their bikes four miles due west. How far is the family from home?
A family rides their bikes four miles due north from home. Then, they ride their bikes four miles due east. How far is the family from home?
The correct answer is the second situation. This is because traveling four miles due east and then four miles due west brings the family back to their starting point, resulting in a net displacement of 0 miles.
In terms of vectors, moving east and then an equal distance west creates opposite vectors that cancel each other out, similar to adding a positive and a negative number of the same magnitude.