I'm working on a little ball launcher project where I have to launch a tennis ball 6 to 10 feet. (No more, no less.) I made a spreadsheet to help me quickly try different distance values at different angles. (I know 45 degrees is optimal, but I wanted the flexibility of trying different angles.) The spreadsheet helps me find the required initial velocity. Here are the values I came up with for the required initial velocity:(adsbygoogle = window.adsbygoogle || []).push({});

The design I'm using is essentially a crossbow. The ball will be placed in achair. Thechairwill be pulled back by a spring that, when released, will accelerate the ball up an incline and lob it the required distance.

My question is... how do I use what I know (which is the initial velocity required) to calculate the required force constant of a spring? And from there, how do I calculate how far back the spring needs to be pulled? And finally, how do I then determine what kind of motor I need which will have enough torque to be able to pull back the spring?

**Physics Forums - The Fusion of Science and Community**

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Calculating spring/motor requirement

Have something to add?

Draft saved
Draft deleted

Loading...

Similar Threads - Calculating spring motor | Date |
---|---|

6D calculation of spring-forces/moments | Feb 9, 2017 |

Impact force calculation of a Full Suspension Mountain Bike | May 21, 2015 |

Force calculation - Gripper (Torsion Spring) | Nov 24, 2014 |

Calculation of the mass springs system | Sep 25, 2014 |

Spring tension calculations | Jun 17, 2014 |

**Physics Forums - The Fusion of Science and Community**