Distance Measures Worksheet

Part 1:

Distance pulse travelled in 5 seconds= _____________________

Speed of the radar pulse (s)=___________________

Length of time for pulse to return to scientist from distant object (t)=________________

Calculated distance (d)=___________________

Part 2:

When the pen is closer, does it move more or less? _______________

When the pen is farther, does it move more or less? _______________

What does this say about the usefulness of parallax at different distances?

What is the farthest object (streetlight or other object) that you can see move relative to the background?_______________

How far away do you think this object is (i.e. what is your estimate of your personal infinity)? _______________________

How far is it actually (by pacing it off)?____________________

Part 3:

Actual height, person 1:____________ person 2:_________________

 Distance Height, person 1 Height, person 2 Measurement 1 Measurement 2 Measurement 3 Measurement 4 Measurement 5

What is the trend in the above angular height measurements?

Did the actual heights change?

Suppose that you had a friend the same height as your lab partner. If you see them on the street, can you figure out how far away they are using this method?

Would this work for galaxies?

Plot your data. Are the points random, or is there a relationship between them?

How reliable is this method for determining distances?

Suppose you used 5 different people at 5 different distances. How would this change your results? How does this relate to the astronomical situation?

Data from streetlight brightnesses:

Person 1:

Person 2:

Plot these data. Is there a trend? Is it the same as in the plot above? Why or why not?

What are your sources of error in this experiment? How do they relate to those in the astronomical context?