A2L Item 258
- Description: Identify which of two travelers take the least time to travel the same distance.
- Goal: Hone the concept of average velocity
- Source: CTtil2;12;02
- Keywords: Velocity, Mechanics
The question for students:
While traveling from Boston to Hartford, Person A drives at a constant speed of 55 mph for the entire trip. Person B drives at 65 mph for half the trip and then drives 45 mph for the second half of the trip. When would B arrive in Hartford relative to A?
- B arrives before A.
- B arrives at the same time as A.
- B arrives after A.
- Not enough information.
Commentary for teachers:
Answer
(3) Many students are inclined to average the speeds and conclude that they arrive at the same time. It is often useful to compare this situation to the one in which time is halved.