- #1
Stevemotto
- 15
- 0
Hey guys, this question has boggled my mind not because I don't know how to approach it but apparently the method I'm using is incorrect!
Question
A cannonball with a mass of 150 kg is fired from a cannon. The cannonball leaves the cannon with 447.9 kJ of kinetic energy. The cannon makes an angle of θ = 25.950 o with the ground as shown in the diagram (not to scale). The castle wall is d = 3820 m from the cannon. Ignore any effects due to air resistance. The acceleration due to gravity is 9.80 ms-2. This castle is built in the future with special building materials that allow it to have very high walls.
What is the speed of the cannonball as it leaves the cannon?My Attempt
So considering I'm given KE & the mass and we want to find the velocity I used the formula KE=1/2(mv^2). I convert kJ to J as required and get 447900 = 1/2(150*v^2), solving for v; v=77.28 m/s.
I enter my solution and apparently it's wrong...
Can anyone evaluate my method and tell me if the system is crazy or I'm just approaching the question incorrectly. I have attached the image to the online quiz showing the question & diagram as well as the system saying I got it wrong when entering the supposed solution.
Kind Regards,
Steven
Question
A cannonball with a mass of 150 kg is fired from a cannon. The cannonball leaves the cannon with 447.9 kJ of kinetic energy. The cannon makes an angle of θ = 25.950 o with the ground as shown in the diagram (not to scale). The castle wall is d = 3820 m from the cannon. Ignore any effects due to air resistance. The acceleration due to gravity is 9.80 ms-2. This castle is built in the future with special building materials that allow it to have very high walls.
What is the speed of the cannonball as it leaves the cannon?My Attempt
So considering I'm given KE & the mass and we want to find the velocity I used the formula KE=1/2(mv^2). I convert kJ to J as required and get 447900 = 1/2(150*v^2), solving for v; v=77.28 m/s.
I enter my solution and apparently it's wrong...
Can anyone evaluate my method and tell me if the system is crazy or I'm just approaching the question incorrectly. I have attached the image to the online quiz showing the question & diagram as well as the system saying I got it wrong when entering the supposed solution.
Kind Regards,
Steven