Question

Sir Dudley the Dextrous is loading cannons on top of the castle's tallest towers in preparation for an expected attack. He slips, and a cannonball of mass 6.00 kg rolls to the edge of the tower, which has a perfectly horizontal surface, and falls to the ground below. It takes the cannonball 1.65 s to fall to the ground, and air resistance is negligible. How much work is done by gravity on the falling cannonball?

Answer 1

Answer:

786 J

Explanation:

Let g = 9.81 m/s2. The vertical distance that the canon ball must have traveled within 1.65 s is (ignoring air resistance):

$h = gt^2/2 = 9.81*1.65^2/2 = 13.35 m$

So the work done by gravity would be the product of gravity force and the distance it traveled

[tex]E_p = Ph = mgh = 6*9.81*13.35 = 786 J