Visual Basic 5.0 Program: "VB Slingshot"

The program VB Slingshot uses the standard Newton's Law to calculate the trajectories of 3 objects based on observations written in Visual Basic 5.0.
Newton's Law assumes that the sum of all the forces of all objects is zero.
Newton's Law law describes that the force between two objects is "equal" to the mass m1 times the mass m2 of each object divided by the distance. Because this force acts twice but in opposite directions as such the sum is zero. Because this is true for all objects and all forces the sum of all forces is zero.

For a more technical explanation about what the slingshot effect is read this: Program 10: Sling Shot Effect and Gravity Assist

VB Program: "VB Slingshot" Operation

The program uses two displays or forms: "Slingshot Control Form" and "Slingshot Simulation Display"

Slingshot Control Display

The VB program is controlled by three Commands: "Select" This Command is used to select the parameter values. "Start" This Command is used to start the simulation. "Cancel" This Command is used to End the execution of the Visual Basic program.

The "Control Display" contains the following four selection parameters:

• Speed parameter has two values: "Up" and "Down"
  value "Up" means "Speed Up" and object m3 will be ejected.
  value "Down" means "Speed Down" and object m3 will stay captured.
• Effect parameter has two values: "Small" and "Large"
  value "Small" means shortest distance is "large".
  value "Large" means shortest distance is "small"
• Update parameter has two values: "Fast" and "Slow"
  value "Fast" means 'Fastest' screen update.
  value "Slow" means slower update when m2 and m3 are at close distances. The intermidiate results are displayed.
• Mass parameter has three values: "0", "20" and "40"
  Value "0" means mass m3 = 0. This is standard value
  m1 = 100000, m2 = 100, m3 is variable.

Simulation Display

When you start the program only the "Control Form" will be displayed. This form shows the "Select" Command in order to modify any of the 4 parameters.
After the parameters are modified (if requested) you select the "Select" Command which will change into the "Start" Command. The "Similation Display Form" will be displayed.

Slingshot Simulation Display

This form shows the following information. The position of the mass m1 in brown. The path of m2 (in yellow) and m3 (in black) in a small layout, slightly right from the center. The path of m2 (in yellow) and m3 (in black) in an enlarged layout, in the center. The distance between m2 and m3 in magenta also in the center. This line is V shaped. At the "bottom" the distance between m2 and m3 is almost zero. The speed v2 of m2 in black at the bottom of the display. In this case with m3 = 0 this path is straight. The speed v3 of m3 in yellow. What this line shows is that the overall speed decreases. There is a bump in the middle to demonstrate that the speed extra increases when m2 and m3 are close together. The speed v3 of m3 in red as a function of the escape velocity. The initial conditions are such that the speed of m3 is below the escape velocity. What the red line shows is that the final speed is above the escape velocity and will be ejected in space.

Simulation Results

The following table shows the result of 12 simulations.
The first 6 simulations demonstrate "Speed UP". The second 6 simulations demonstrate "Speed Down".
The first 3 simulations with "Speed UP" demonstrate a "small" effect. The second three the "large" effect. The same with "Speed Down"

Nr	Speed	Effect	Mass	V3 str	V3 end	V3 escape	R avr	R min
1	Up	small	0	51,63	44,89	38,59	99.999	0,3476
2	Up	small	20	51,63	44,75	38,60	99.718	0,3417
3	Up	small	40	51,63	44,61	38,62	99.450	0,3358
4	Up	large	0	51,63	60,45	37,74	99.999	0,0666
5	Up	large	20	51,63	58,30	37,98	99.433	0,0624
6	Up	large	40	51,63	56,16	38,21	99.107	0,0584
7	Down	small	0	51,63	34,64	39,67	99.999	0,4442
8	Down	small	20	51,63	34,55	39,68	100.222	0,4381
9	Down	small	40	51,63	34,46	39,69	100.452	0,4322
10	Down	large	0	51,63	28,49	40,64	99.999	0,1604
11	Down	large	20	51,63	27,92	40,69	100.642	0,1551
12	Down	large	40	51,63	27,39	40,73	101.311	0,1499

• The difference between test 1,2 and 3 is the mass of m3.
  When you compare the column "V3 end" with "v3 escape" you will observe that "V3 end" is larger than "v3 escape", which means that m3 will escape from this system.
  When you consider "R avr", which is the average distance from m2 to m1, you will observe that this distance decreases as a function of m. That means m2 approaches m1 while m3 is ejected.
• When you compare the tests 7 to 9 with the test 1 to 3 the reverse is observed: v3 end (final speed of m3) is always smaller than the escape velocity and "R avr" increases as a function of Mass. That means the distance between m2 and m1 increases, while m3 approaches m1.
• When you consider the tests 4-6 ("Speed Up" and "Effect large") and you study "R min" than these values are much smaller than the tests 1-3. This is as expected because what you try to simulate are conditions where m3 almost collides with m2.
• When you perform test 1 with Update parameter = "Slow" you get a good impression that m3 passes m2 from behind. The result will be that the speed of m3 will increase.
• When you perform test 7 with Update parameter = "Slow" you get a good impression that m3 passes in front of m2 . The result will be that the speed of m3 will decrease.

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VB Program: "VB Slingshot" executable

In order to get the Visual Basic 5.0 executable program use the following zip file:VB Slingshot.zip
The Visual Basic Executable program requires MSVDVM50.DLL: Msvdvm50.dll.zip

There is also a QBASIC program "slinshot.bas" available to demonstrate the "slingshot effect". For a description select: slingshot.htm.
In order to get a copy of the program "slinshot.bas" select: slinshot.zip. This zip file also contains the executable: "slinshot.exe"

Reflection

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