Kevin S. Huang

2011: Problems 2-4

Topic: Kinematics
Concepts: Motion graphs

Solution:

Recall the average acceleration is given by

\bar{a}=\frac{\Delta v}{\Delta t}

which on a $v$ – $t$ plot corresponds to the slope of the line connecting the beginning and end points.

In our case, the magnitudes of the slopes are equal for all three objects so the answer is E.

Topic: Kinematics
Concepts: Motion graphs

Solution:

Recall the maximum velocity corresponds to the maximum value of the graph for a $v$ – $t$ plot.

In our case, we find from the plots

v_{1,\text{max}}>v_{2,\text{max}}=v_{3,\text{max}}

Since these quantities are all positive, taking the magnitudes leaves the ranking the same. Thus, the answer is D.

Topic: Kinematics
Concepts: Motion graphs

Solution:

Recall distance corresponds to the unsigned area under the graph for a $v$ – $t$ plot.

In our case, we find from the plots: $d_1=18, d_2=19, d_3=14$ so

d_2>d_1>d_3

Since these quantities are all positive, taking the magnitudes leaves the ranking the same. Thus, the answer is B.