Tamara- AP Physics
Exercise 1: Going airborne
1. When the helicopter is moving at a constant velocity, is there a net force acting on it?
No, there is no acceleration.

2. The helicopter first moves up, and then you caused it to hover (or attempted to cause it to hover). Did there have to be a negative net force acting on the craft at some point for this to occur? Why?
Yes, the velocity has to come back to zero after you get it off the ground. The only way for the velocity to be zero if it is positive is to have a negative net force.

Exercise 2: What is the mass of the helicopter?  

                                                           Force                                                Acceleration

Data point 1                                 2000 N                                                        .98

Data point 2                                -2000 N                                                      -.98

3. Does the acceleration change with the net force? What is the mathematical relationship of acceleration and net force?
Yes. Acceleration equals the force divided by the mass.

4. What is the mass of the helicopter? How did you determine it?
I will use the equation to determine the mass: Force= Mass* acceleration 2000= m*.98 Mass= 2040.816 kg

Exercise 3: Net force and acceleration

5. What lift force was required to save the day?
32,000 N

Exercise 4: Air resistance    

                                                       Speed                                           Force

Data point 1                            11.18 m/s                                     1000 N

Data point 2                            15.85 m/s                                     2000 N

Data point 3                            25.10 m/s                                     5000 N

Data point 4                              7.87 m/s                                        500 N

6. Look at your data. How does the force of air resistance vary with the speed of the helicopter? Does the force of air resistance increase as helicopter speed increases, decrease as helicopter speed increases, stay the same, or is there no relationship at all? Use your data to justify your answer.
The air resistance increases as the speed increases. For example, at 500 N my speed was 7.87 m/s, but at 5000 N my speed was 25.10 m/s. The speed increases as the force increases.

7. Using the guidelines above, is the relationship between air resistance force and helicopter speed a linear, inverse, or squared relationship? Or is there no relationship at all? Justify your answer using your data.

It is a squared relationship because as the force goes up the speed goes up exponentially.

Exercise 5: Flying your helicopter

8. What horizontal thrust force is required for the helicopter to have zero horizontal velocity? To be moving at a constant horizontal velocity?
Zero for both because the horizontal velocity will change unless the thrust force is zero.

Exercise 6 (optional): Save the day!

9. What is the required lift force? Given this lift force, what are the net horizontal and vertical forces?
The required lift force is 25,500 N. The net vertical force is 25112.6 N. The net horizontal force is 4428 N.