Kingda ka at six flags has a 55m drop. The rollercoaster has a mass of 8000kg. How fast it be travelling when it reaches the bottom?
1 Answer
Explanation:
We know from Galileo that mass doesn't effect how fast things fall to Earth. There's the famous experiment of dropping a feather and a hammer and both should fall to the ground at the same time (if there isn't vacuum). This was done by Apollo 15:
Therefore, we only use constant gravitational acceleration. The mass is only given to you as a distraction. This means we can use familiar formulae for constant acceleration.
The most useful one is
which can be proven by the fact that
So now we can use this formula for Kingda Ka. You start at rest (meaning
Sidenote: I don't know if you've learned about energy yet, but energy also makes this argument pretty simple. We equate our initial and final energies and get the exact same formula: