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heres the prob:

A 21.0 kg cannon ball is fired from a cannon with a muzzle speed of 1100 m/s at an angle of 37.3° with the horizontal. A second ball is fired at an angle of 90.0°. Use the law of conservation of mechanical energy to find

(b) the total mechanical energy at the maximum height for each ball. Let y = 0 at the cannon.

in (a), i had to find the height for each ball, which i did using ( mv^2/2 ) - mgh = 0

i found the first ball to be 2.27e4 m/s (using 1100sin37.3)

and the second ball to be 6.17e4

now i can find the mech energy

do you use ( mv^2/2 ) + mgh = Mech E

(i simplified changed in PE and changed in KE in the above equation)

and then add the two Mech Energies?

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# Homework Help: Mechanical energy of cannon ball

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