Calculating Force in a Human Cannonball Act: How Is It Done?

[asianygoodnes]

Homework Statement

During a circus performance a 72 kg human cannonball is shot out of an 18m long cannon. If the human cannonball spends .95 s in the cannon, determine the average net force exerted on him in the barrel in the cannon.

Homework Equations

f=ma
x=v0t + 1/2 at^2 (?)

The Attempt at a Solution

So i solved for acceleration using the kinematics equation, assuming that v0=0
i got approximately 40 m/s^2 and multiplied that by the mass of the man
I got about 2900 N. Is this a good answer? Or did I confuse myself, as usual, when it comes to physics.

 

[ehild]

Your solution is correct.

ehild

 

[kerimek]

Great job using the kinematics equation to solve for acceleration! Your answer of 2900 N is correct. To answer the question of how to use the force in this situation, the force is being exerted on the human cannonball by the cannon. This force is what propels the human cannonball out of the cannon and into the air. In order to achieve the desired result, the force must be strong enough to overcome the force of gravity and any other resistive forces. In this case, the force was strong enough to launch the human cannonball a distance of 18m in just 0.95 s, which is quite impressive!