Middle School Physics: Adrift
Step 3: Practice Calculations
Adding Vectors

Adrift
Imagine that a group of middle school students is taking a field trip aboard a research vessel off the coast of New Jersey. The vessel is caught in a sudden storm and the engine breaks down, leaving the students adrift at sea for three days before the Coast Guard can rescue them (don't worry--they have plenty of food!). The last known location of the vessel is 10 miles East of Ocean City, NJ. Record all your answers on the Adrift Activity Worksheet under "Adding Vectors".

The location of the boat is indicated on the map by a red dot approximately 10 miles off shore.

1. Click on the thumbnail below to enlarge the map and have your "Adrift" Activity Worksheet ready to answers the questions under "Adding Vectors".

2. Look at the vector for Day 1. To determine how far the boat drifted in the first 24 hours, measure the length of the vector for Day 1 in centimeters (cm). Use the conversion of 1 cm = 21.4 cm/sec and convert to km/hr using the C.O.O.L. Room "Speed Conversion" calculator. Then multiply your answer by 24 hours to obtain the distance traveled on Day 1. Repeat the calculations for the vectors for Days 2 and 3.

3. Draw a straight line connecting the starting point on Day 1 to the ending point on Day 3. This line is the resultant vector. Measure the length of the vector in cm, and then use the scale 1 cm = 18.5 km to calculate the distance between the two points.

Analysis:
Answer the following questions on the Adrift Activity Worksheet under "Adding Vectors".

1. Add the component vectors from each of the three days to determine the total distance the boat drifted

2. How far from the starting point was the boat eventually located? How does this differ from adding the component vectors over the three days?