Question

The Goliath six flags Magic Mountain roller coaster ride starts at 71.6 m (235 feet) above the ground. Assuming the coaster starts from rest and ignoring any friction, what is the speed of the coaster when it reaches the ground level

Answer 1

Answer:

The  velocity is $v = 37 .46 \ m/s$

Explanation:

From the question we are told that

    The start distance above the ground is  $h = 71.6 \ m$

Generally according to the  law of energy conservation we have that

     $PE_{top} = KE_{bottom }$

Where $PE_{top}$ is potential energy at the top which is mathematically represented as

      $PE_{top} = m * g * h$

And  $KE_{bottom }$ is the kinetic energy at the bottom which is mathematically represented as

     $KE_{bottom } = \frac{1}{2} * m * v^2$

Therefore  

       $m * g * h = \frac{1}{2} * m * v^ 2$

=>    $v = \sqrt{2 * g * h }$

substituting value

     $v = \sqrt{2 * 9.8 * 71.6 }$

     $v = 37 .46 \ m/s$