PHYS 1405 – Conceptual Physics I
Introduction to Motion Activity
This activity will introduce how we describe motion. You will work in groups of 5-6 for this activity. We will time ourselves as we walk along a straight line recording our time every 2 m.
Materials
4-5 stopwatches per group
1 x 5 m tape per group
1 roll masking tape per group
1 x sheet of graph paper per person
Procedure
1. Use the masking tape to mark equal distance intervals 2 m apart along a straight line.
There should be as many marks as people in the group.
2. Each person in the group should take a turn doing the following. Each person except for the walker should have a stop watch and should stand next to a mark. No one stands next to the first mark. The walker starts far enough away from the first mark so that they are traveling at a constant speed by the time they reach the first mark and continues past each successive mark at a constant speed. As the walker passes the first mark, he/she says go and all the timers starts their watch. As the walker passes the mark manned by a timer, the timer stops the watch. After the walker has passed all of the timers, everyone should record the time the walker passed each successive mark. Note that we start the watches at the first mark, so a time of 0 s is already filled in. Different walkers should move at different speeds as shown in the table below.
Record the name of the walker and the time they passed each mark in the table below.
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Painfully slow |
Slow |
Medium |
Medium Fast |
Really fast |
Running |
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Name of |
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0 m |
0 s |
0 s |
0 s |
0 s |
0 s |
0 s |
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2 m |
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4 m |
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6 m |
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8 m |
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10 m |
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Questions
Q1) In this activity, the walkers all traveled the same distance between successive marks. Were the times longer for fast or slow walkers?
Q2) Explain why this is the case.
Q3) The goal was for each walker to travel at approximately a constant speed. Examine the time data for each walker. Were the walkers successful at traveling a roughly constant speed? Explain your answer based on the time data. (Hint: If the walkers traveled at a constant speed, then how should the time change for each additional 2 m of distance?)
D4) Each person should make a graph of Distance vs. Time (distance on the y-axis and time on the x-axis). The graph should include the data for each walker. You should use a different symbol such as circles, triangles, stars, etc. for the data from different walkers. Be sure your graph includes the following.
1. Labeled axes with units
2. Title
Q5) What feature of the graph shows that the walkers traveled at an approximately constant speed?
Q6) How is the graph different for faster walkers than slower walkers?
Q7) Complete the following. The graph of distance vs. time for a person moving at constant speed is a ____________. The slope is ____________ for faster walkers than slower walkers.
It seems that the slope is related to the speed of the walker. In fact, the average speed is defined to be the slope of the graph of distance vs. time. For the data we took above, we can find the average speed by using the total distance traveled by the walker divided by the total time, or in symbols v = d/t. Complete the following table below.
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Distance |
Time |
Speed |
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