Based on the law of conservation of energy, how can we reasonably improve a machine’s ability to do work?
move the machine to a different gravitational field.
increase the friction between its moving parts.
reduce the friction between its moving parts.
redefine the machine’s system boundaries

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.