Question

If an 800 kg roller coaster is at the top of its 50 m high track, it will have a potential energy 392,000 and a kinetic energy of 0J. This means the total mechanical energy is 392,000J. If the cart drops down to a new height of 10m, how much energy does the cart have now?

Answer 1

313600 J

Explanation:

We have that the gravitational potential energy is given by the following equation:

`E_p=m\cdot g\cdot h`

We substitute and calculate the potential energy, knowing that g is the acceleration of gravity and is equal to 9.8 m/s^2:

`\begin{gathered} E_p=800\cdot9.8\cdot10 \\ E_p=78400\text{ J} \end{gathered}`

We know that the total energy is 392,000 joules, so the energy it now carries would be the total minus the calculated potential energy:

`\begin{gathered} E_k=392000-78400 \\ E_k=313600\text{ J} \end{gathered}`

The energy carried by the cart is 313600 J