# Homework Help: A force/acceleration problem

1. Nov 8, 2007

### Rylynn97

During the performance of the Bouglione circus in 1976, John Tailor was fired from a compressed-air cannon whose barrel was 20m long. Taylor emerged from the cannon at 40 m/s. If Tailor's mass was 70kg, find the force on him during the firing of the cannon.

I'm at a loss for what to do. I understand that in order to get the force I must get the acceleration first. What's the relevance of the length of the barrel to the computations? How should I proceed? Thank you! ^__^.

2. Nov 8, 2007

### Astronuc

Staff Emeritus
Well, force F is just mass times acceleration, or F = ma. We know the mass, so we must find the acceleration.

Now all we have to do is think of the appropriate equation of motion to use.

We know he starts at rest so v0 = 0, he emerges from the cannon at v=40 m/s, and the distance over which he is accelerated is 20 m.

So, what equation do we use?

http://hyperphysics.phy-astr.gsu.edu/hbase/mot.html#mot1