The AMOUNT of energy the ball has doesn't change. It's 294 joules in Darwin's hand, and it's still 294 joules when the ball hits the ground. It's all PE before he let's it go, and it steadily changes from PE to KE all the way down.
It BEGINS to turn into KE immediately, when Darwin lets go of the ball, and it starts to fall.
More and more PE turns into KE as the ball falls, all the way down.
When the ball hits the ground, it has no more PE left. All of its mechanical energy is then KE.
Terrorist attacks on the United States is the answer.
On September 11, 2001 that was the day New York got attacked by terrorists. The Twin Towers were the ones that got affected, 2,996 people (maybe more) died during that attacked. The terrorists were one of the 2,996 people that died (19 of them died). more than 6,000 were injured that day.
#NeverForget
Hope this helped
Have a great day<span />
Explanation:
The machine whose efficiency is 100% is known as perfect machine .This machine is not possible in real life because every machine is affected by the overcoming friction due to which is efficiency become less than hundred percent .