# Space Pod Lab

 Materials: Computer and School Network Time Allotment: 3 Class Days

### Purpose:

The purpose of this lab is to investigate the relationship the x- and y-components of a force and its effect upon the x- and y-components of the velocity of a space pod.

This lab must be done on a Macintosh computer connected to the school network or upon a computer in the Science Computer Lab; if you have difficulty accessing the file from a GBS computer lab, then use the computers in the Science Department. To prepare for the lab, do the following steps.

• Log onto the school network in the usual manner.
• Open the Interactive Physics application.
• Choose Open... from the File menu. Navigate to the Hewitt Simulations folder and open the file titled Space Pod by double-clicking on its name.

### Situation A:

Colleen and Alex are astraunauts in a small space transport called a space pod. Their supplies of fuel and food are running low and they need to make some repairs to the space pod. They can get food, fuel and make repairs by docking at an unmanned deep-space supply station. Colleen and Alex need to precisely fire four seperate rocket thrusters in the correct combination to dock at the food and fuel ports and to enter the repair bay. The space pod must line up exactly with the docking port and it must be traveling slowly enough for the docking to be successful. The rockets only fire for a brief period to get the space pod moving; after firing, the space pod travels with a constant speed.

### Make a Prediction:

1.Predict the correct values for the x and y components of the rocket thrusters that will allow the space pod to dock at the repair bay. Colleen and Alex's initial position is (x=0, y=0). Note: to travel to the left on the screen, use a negative x component; to travel downward on the screen, use a negative y component. Record your predictions below.

X rocket thrust = ________________ N

Y rocket thrust = ________________ N

 Run Simulation: Set X rocket thrust and Y rocket thrust to the values you predicted in Question 1. Click the Run button and observe the simulation. If your docking at the repair bay is unsuccessful, predict new x and y rocket thrust components and repeat the simulation. After successfully docking, repeat the simulation to find if any other values for X rocket thrust and Y rocket thrust will result in a successful docking. Remember to click the Reset button before setting the new rocket thrust values.

2. Explain how changing the magnitude of the X rocket thrust affects the speed and direction at which the space pod travels.

3. If too much thrust is applied, the space pod will attain a speed that is too fast to permit a successful docking. Determine the maximm value of the resultant thrust vector that permits successful docking at the repair bay by running the simulation as directed below.

 Run Simulation: Click the Reset button. Set X thrust to 5.00 x 10^3 N and Y rocket thrust to 0.00 x 10^3 N. Click the Run button and observe the successful docking. Continue repeating the simulation while increasing the value for X rocket thrust until an unsuccessful docking occurs. Remember to click the Reset button before setting the new rocket thrust values. Record below the highest value of X rocket thrust that resulted in a successful docking.

 Highest value for X Rocket Thrust that resulted in a successful docking = Maximum allowable resultant thrust vector =____________ N

4.Shown below are sets of x and y rocket thrust components for a course to the Fuel depot docking port. For each individual diagram, the magnitude of the x- and y-components are the same. In the space below, calculate the magnitude of each resultant thrust vector. PSYW

5.Which sets of x and y rocket thrust components in Question 4 will result in a successful docking? Refer to the maximum allowable resultant thrust vector in Question 3 and explain your answer fully.

### Make A Prediction

6. Predict two sets of correct values for the x and y rocket thrust components that will allow the space pod to dock at the Food depot. Colleen and Alex's initial position is (x=0, y=0). Note: To travel to the left on the screen, use a negative x component; to travel downward on the screen, use a negative y component. Record your predictions below

Set 1 X rocket thrust = Y rocket thrust=

Set 2 X rocket thrust = Y rocket thrust=

 Run Simulation: Click the Reset button. Verify your predictions. Set X rocket thrust and Y rocket thrust to the values you predicted in Question 6. Click the Run button and observe the simulation. If your docking at the Food depot is unsuccessful, predict new x- and y-rocket thrust components and repeat the simulation. Remember to click the Reset button before setting the new rocket thrust values

Questions #7-10 refer to the three vector diagrams below.

7. Use the Pythagorean Theorem to calculate the magnitude of the resultant thrust vector for each of the three thruster settings. Show your work in the space provided.

8. On a separate sheet of paper, use an accurately-drawn scaled vector diagram to determine the resultant thrust vector for each of the three thruster settings. Indicate the scale and label the magnitude of all vectors including the resultant.

9. Which of the thruster settings will result in a successful docking at the Food depot? Explain.

10. If there is only enough fuel to provide a total of 6.5x10^3 N of thrust, which of the thruster settings can the space pod perform? Explain.

### Conclusion:

Based on this activity, summarize how the idea of vectors can be used to solve physics problems. In your summary, give one original application of the use of vectors to analyze a real-world physical situation.

This page created by Tom Henderson and last updated on 9/26/97.

Special thanks to lab assitant Dan Reid for assistance with the typing.