Final answer:
The girl's displacement, after riding 12 miles east and then 7 miles west, is 5 miles to the east, because displacement accounts for the overall change in position and direction.
Step-by-step explanation:
To calculate the displacement of the girl on her bicycle ride, we consider the direction of her travel and the distance covered in each direction. First, she travels 12 miles east, and then she turns around to travel 7 miles west. Displacement in physics is the straight-line distance between the starting point and the ending point, taking direction into account. The calculation here would be:
- Eastward trip = +12 miles (we use positive for east)
- Westward trip = -7 miles (we use negative for west)
Add these two values to find the girl's total displacement:
Displacement = Eastward trip + Westward trip
Displacement = +12 miles + (-7 miles)
Displacement = +5 miles
Therefore, the girl's displacement is 5 miles to the east. It is important to note that displacement is different from distance traveled, as displacement considers the net change in position.