Question

A computational model predicts the speed of a roller coaster car at different heights given its speed at the lowest height of its journey, which is at ground level. The speed at the lowest point is 30 m/s. What is the prediction for its speed when it is at a height of 20 m?(1 point)

18.8 m/s

15.9 m/s

37.5 m/s

22.5 m/

Answer 1

The answers to this test are:

1. What is the maximum speed when the conditions are mass = 450 kg, initial height = 30 m, and the roller coaster car is initially at rest?

24.2 m/s

2. A computational model predicts the maximum height that a roller coaster car can reach when the lowest height of its journey is at ground level, where it has a speed of 20 m/s. Given these conditions, what is the maximum height?

20.4 m

3. A computational model predicts the speed of a roller coaster car at different heights given its speed at the lowest height of its journey, which is at ground level. The speed at the lowest point is 30 m/s. What is the prediction for its speed when it is at a height of 20 m?

22.5 m/s

4. A computational model predicts the maximum potential energy a roller coaster car can have given its mass and its speed at the lowest point of its journey. Its mass is 350 kg, and it speed at a height of 0 m is 25 m/s. What is the prediction for its maximum potential energy?

109,375 J

5. What is the benefit of using simple computational models in a spreadsheet application, like the one used in this course, to predict mechanical energy and related values?

It is easy to calculate new scenarios.

Answer 2

The predicted speed of roller coaster at the given height is 22.5 m/s. Hence, option (d) is correct.

Given data:

The speed of roller coaster at the lowest point is, v = 30 m/s.

The height of coaster is, h = 20 m.

We need to predict the speed at the given height. So for that purpose, we can use the law of conservation of energy. As per the conservation of energy :

Total energy at height of 20 m = Total energy at bottom

PE + KE = PE' + KE'

Here,

PE and KE are the potential and kinetic energies at respective points.

So,

$mgh + \dfrac{1}{2}mv'^{2}=0 + \dfrac{1}{2}mv'^{2}$

At bottom, the potential energy is zero.

Solving as,

$gh + \dfrac{1}{2}v'^{2}=\dfrac{1}{2}v^{2}\\\\(9.8 \times 20) + \dfrac{1}{2} \times v'^{2}=\dfrac{1}{2} \times 30^{2}\\\\v' = 22.5 \;\rm m/s$

Thus, we can conclude that the predicted speed of roller coaster at the given height is 22.5 m/s. Hence, option (d) is correct.

Learn more about the conservation of energy here:

https://brainly.com/question/2137260