Sir Dudley the Dextrous is loading cannons on top of the castle\\\'s tallest tow

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 18.0 kg cannonball 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 seconds to fall to the ground, and air resistance is negligible. How much work is done by gravity on the falling cannonball? During the fall, what is the average power transfer to the cannonball due to the force of gravity?

Explanation / Answer

Here ,

time taken to fall , t = 2.15 s

mass of ball is m = 2 Kg

let the height of tower is h

Using second equation of motion

h = 0.5 at^2

h = 0.5 * 9.8 * 2.15^2

h = 22.7 m

Now, work done by gravity = m * g * h

work done by gravity = 22.7 * 9.8 * 2

work done by gravity = 444 J

the work done by gravity is 444 J

Now , for the average power

average power = work done/time

average power = 444/2.15

average power = 206.5 W

the average power transfer to the cannonball due to the force of gravity is 206.5 W

Related Questions

Navigate

• Browse (All)
• Browse S
• Subjects