Scalars and Vectors in One Dimension AP Physics 1 MCQ – Exam Style Questions etc.
Scalars and Vectors in One Dimension AP Physics 1 MCQ
Unit: 1. Kinematics
Weightage : 10-15%
Exam Style Practice Questions, Scalars and Vectors in One Dimension AP Physics 1 MCQ
Answer/Explanation
Ans:B
The distances between the dots represent the speed of the cart. The dots first get farther apart, indicating an increasing speed to the right. This indicates an acceleration to the right. Next, the dots are approximately equally spaced in the middle. This indicates an acceleration of zero. Then the dots get closer together, indicating a decreasing speed to the right. This indicates an acceleration to the left.
Question
In an experiment, an object is launched with an initial velocity in the vertical direction. Its position as a function of time is recorded as dots on a piece of paper, as shown, with the downward motion offset to the right of the upward motion. Students draw the velocity vectors shown to represent the speed and direction of the object as it moves. Which of the following correctly describes the relationship between the dots and the vectors?
A The dots are getting higher over time, so the students’ vectors should get longer at higher positions, not smaller.
B The dots are getting higher over time, so the students have correctly shown the vectors getting smaller at higher positions.
C The dots are getting closer together on the way up and farther apart on the way down, so the students should show the vectors getting longer on the way up and shorter on the way down, the reverse of what is shown.
D The dots are getting closer together on the way up and farther apart on the way down, so the students have shown the vectors getting shorter on the way up and longer on the way down.
E Since the dots show the object moving in free fall, the students should draw all the vectors as the same size.
Answer/Explanation
Ans:D
On the way up, as the object gets higher, the dots get closer together. This indicates that the speed for each time interval is decreasing, so the vectors should be getting smaller. On the way down, as the object gets lower, the dots get further apart. This indicates that the speed for each time interval is increasing, so the vectors should be getting larger.