I'm stuck on cannon ball qusetion can any one help

[jgerco]

the question is how far away was a cannonball fired?

we know that the
-cannonball ricocheted along the ground an unknown amount of times before hitting the persons kneecap and shattering it.
-a three pound cannon ball has a mass of 1.36kg
-the maximum range of the cannon is 1125m
-the maximum elevation of the cannon is 30 degrees
-the cannon was on flat ground
-acceleration due to gravity is 9.8 ms-2
-no air resistance
-a kneecap is 1 cm thick
-the force needed to break a kneecap is 12000 N
-the cannon ball was about to hit the ground
-the cannon muzzle was at the same height as his knee
-the angle of incidence and reflection are the same 30 degrees for evry time it hits the ground
-each time the ball hits the ground its kinetic energy is reduced by 75%

any help to this question would be much appreciated and if you think you have the answers to my question could you please e-mail me at mmm_freak@yahoo.com.au thank you

 

[Andrew Mason]

the question is how far away was a cannonball fired?

we know that the
-cannonball ricocheted along the ground an unknown amount of times before hitting the persons kneecap and shattering it.
-a three pound cannon ball has a mass of 1.36kg
-the maximum range of the cannon is 1125m
-the maximum elevation of the cannon is 30 degrees
-the cannon was on flat ground
-acceleration due to gravity is 9.8 ms-2
-no air resistance
-a kneecap is 1 cm thick
-the force needed to break a kneecap is 12000 N
-the cannon ball was about to hit the ground
-the cannon muzzle was at the same height as his knee
-the angle of incidence and reflection are the same 30 degrees for evry time it hits the ground
-each time the ball hits the ground its kinetic energy is reduced by 75%

any help to this question would be much appreciated and if you think you have the answers to my question could you please e-mail me at mmm_freak@yahoo.com.au thank you

Kind of an odd question. But it provides some little clues.

Use the information about the cannon ball trajectory to determine the muzzle velocity of the cannon ball. Since the ball hits the ground with an angle of incidence of 30 deg. what does that tell you about the firing angle?

The problem with this question is that the cannon ball can break the knee on any number of bounces, so I don't see that there would be just one answer.

AM

 

[kyle8921]

I can provide some guidance on how to approach this question. First, we need to consider the physics involved in the situation. The cannonball's trajectory can be described using the equations of projectile motion. We know the initial velocity of the cannonball (based on the maximum range and elevation of the cannon) and we can calculate the time it takes for the cannonball to reach the ground using the equation t = 2Vsin(theta)/g, where V is the initial velocity, theta is the angle of elevation, and g is the acceleration due to gravity.

Next, we need to take into account the ricochets and the reduction in kinetic energy each time the cannonball hits the ground. This will require some calculations using the conservation of energy and the coefficient of restitution (which describes the amount of energy lost during a collision).

Finally, we need to consider the force needed to break a kneecap and the thickness of the kneecap. This will allow us to determine the distance at which the cannonball would have enough energy to shatter a kneecap.

It would be helpful to have more information, such as the initial velocity of the cannonball and the angle at which it was fired. If you have this information, please provide it so we can assist you better.

In the meantime, I suggest you review the equations for projectile motion and conservation of energy, and try to apply them to this situation. If you have any further questions or need clarification, please feel free to reach out to me or consult with a physics teacher or tutor. Good luck!