Force transfer from compressed spring

1. Jun 28, 2012

Neil Burns

1. The problem statement, all variables and given/known data
I have a metal spring 50mm in diameter 152 mm long compressed to half its length ie 76mm by using a weight of 50kg. I have used a clip to hold it compressed. When that clip is broken the spring will expand back to its original length of 152mm. How can I work out how far it will push a tennis ball weighing 1kg into the air and how long will this take ?

2. Relevant equations
Newton Acceleration = force/mass
Speed = distance/time s=d/t
acceleration= increase in speed over time (speed end -speed beg) / (time end-time beg)

Please let me know what other equations I should use?

3. The attempt at a solution
The tennis ball will accelerate very fast to begin with at rate of 50kg - 1kg but slow as the force of gravity drags it back to the earth

2. Jun 28, 2012

tiny-tim

Welcome to PF!

Hi Neil! Welcome to PF!

Use conservation of energy to find when the ball leaves the spring (that'll be when the acceleration = … ?)

Then use one of the standard constant acceleration equations.

3. Jun 28, 2012

LawrenceC

A tennis ball of mass 1 kg? What is inside of it?

4. Jun 28, 2012

tiny-tim

baked beans! :tongue2: