When energy is converted from one form to another in a chemical or physical change, which of the following also changes by a measureable amount? select the correct answer below:

a. the total mass in the system
b. the force of gravity
c. the total energy
d. none of the above

During a medieval siege of a castle, the attacking army uses a trebuchet to hurl heavy stones at the castle walls. if the trebuchet launches the stones with a velocity of at an angle of 50.0°, (a) how long does it take the stone to hit the ground? (b) what is the maximum distance that the trebuchet can be from the castle wall to be in range? (c) how high will the stones go? show all your work.