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 14.0 kg 14.0 kg rolls to the edge of the tower, which has a perfectly horizontal surface, and falls to the ground below. It takes the cannonball 3.15 s 3.15 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:

6667.9 J

Explanation:

We are given that

Mass of cannon.m=14 kg

Time,t=3.15 s

Initial velocity,u=0

We have to find the work done by gravity on the falling cannon ball.

$g=9.8 m/s^2$

$h=ut+\frac{1}{2}gt^2$

Substitute the values

$h=0+\frac{1}{2}\times 9.8\times (3.15)^2=48.6 m$

Work done,W=mgh

Using the formula

$W=14\times 9.8\times 48.6=6667.9 J$