# Soccer physics

1. Jan 16, 2010

### JohntheGreat

How much Force and at what velocity it would take to kick a soccer ball that weights 290 grams or .64 lbs in an arc for a distance of 20 feet, 30 feet, and 40 feet?

-Can you include the formulas for what the angle would need to be to kick the ball those three distances too.

2. Jan 16, 2010

### tiny-tim

Welcome to PF!

Hi JohntheGreat! Welcome to PF!

Use F = ma and the standard constant acceleration equations.

Show us what you get.

3. Jan 16, 2010

### JohntheGreat

I would appreciate a little more help thank you

4. Jan 16, 2010

### Yitzach

What angle did you have in mind, or were you going to minimize force? In that case, the angle would be 45 degrees as the ball is on the ground. It will be something less if it is in the air.
What is the distance or time duration of the applied force?
Is the force constant for the time of application?
Is the force constant between applications? Sounds like it, but the fewer things assumed, the happier we are with the results.

5. Jan 16, 2010

### xxChrisxx

We aren't here to do your homework John (and this look ultra suspiciously like a research assignment). Tell us what you think.

Also is this a highy idealised case, or a real case you are considering? As the common answer of 45 degrees doesnt hold true for a real case.

I'd suggest you do a cursory sweep of google before coming back, there are some very good sites on football trajectories and general principles behind the kicking of a spherical ball. Think about what assumptions are being made too.

Last edited: Jan 16, 2010
6. Jan 17, 2010

### JohntheGreat

I am building a robot my FIRST Robotics team here is a link to the competition this year I have not taken Physics yet and any help or guidance would be very appreciative. Also I am trying to design a Pneumatic launching device and to do this I need the answers to this questions to order the correct pneumatic piston.

Last edited by a moderator: Sep 25, 2014
7. Jan 17, 2010

### xxChrisxx

Ah I see. Using the kinematic equations you can find the flight time for a ball with a set launch velocity.
http://www.physicsclassroom.com/class/1DKin/u1l6a.cfm

From this you can also work out the angle needed for a set launch speed. To get the required lauch speed depends on the launching mechnicam.

As you mention a pneumatic piston you can simply use convervation of momentum.
http://en.wikipedia.org/wiki/Momentum#Conservation_of_linear_momentum

You will have to factor in the loss due to the coefficient of restitution of the ball to piston contact (ie some energy will be lost).
http://en.wikipedia.org/wiki/Coefficient_of_restitution

You can then work out the amount of air pressur eneeded to accelerate the piston to the required speed in the space available from F=Ma