Question

Please help giving a lot of points- A rollercoaster cart that has a mass of 4500 kg has 67.5 kJ (kilojoules), or 67,500 J (joules), of gravitational potential

energy. What is its height above the ground?


PT.2


The same 4500 kg rollercoaster cart is moving with 63.0 kJ (kilojoules), or 63,000 J (joules), of kinetic energy at the


bottom of its biggest hill. What is its velocity?

Answer 1

Answer:

(a) h = 1.5 m (b) v = 5.29 m/s

Explanation:

1. Given that,

Mass of a rollercoaster cart, m = 4500 kg

It has 67,500 J of gravitational potential  energy.

We know that, the gravitational potential  energy is given by :

$E=mgh$

Put all the values,

$h=\dfrac{E}{mg}\\\\h=\dfrac{67500}{4500\times 10}\\\\h=1.5\ m$

2. The kinetic energy of an object is given by :

$E=\dfrac{1}{2}mv^2\\\\v=\sqrt{\dfrac{2E}{m}}\\\\v=\sqrt{\dfrac{2\times 63000}{4500}}\\\\v=5.29\ m/s$

Hence, this is the required solution.