Mathematics
Grade Levels: 6th Grade, 7th Grade, 8th Grade, 9th Grade, 10th Grade, 11th Grade, 12th Grade,
Topics: AlgebraExpressions and Equations
Common Core State Standard: A-REI.2,
Knowledge and Skills:
• Can evaluate expressions by substituting values for variables
• Can simplify expressions using correct order of operations
• Can do basic operations on both sides of an equation in such a way as to preserve the equality
Lesson:
Answers:
1.
| h (meters) | v (meters/sec) |
| 15 | 26.2 |
| 40 | 14.0 |
| 35 | 17.1 |
| 5 | 29.7 |
| 30 | 19.8 |
| 50 | 0.0 |
| 25 | 22.1 |
| 20 | 24.2 |
| 45 | 9.9 |
| 10 | 28.0 |
| 0 | 31.3 |
2. 31.3 meters/sec
3. No. For the 50 foot roller coaster, the increase in velocity in the first half of the fall (from h = 50 feet to h = 25 feet) is 22.1 meters/sec. The increase in velocity in the second half of the fall (from 25 feet to 50 feet) is only 9.2 meters/second (31.3 – 22.1). So the velocity does not double when the length of the drop doubles.
The Drop
Suppose a roller coaster ride begins by climbing to a height of 50 meters, stopping briefly, and then falling rapidly to ground level (a height of 0 meters).
As it falls the roller coaster will gain speed.
If you ignore the effects of friction, then height and speed are related by this equation:
50 – h = v²/19.6
(h = height in meters, v = velocity in meters per second).
1. Find the missing values in the table below:
| h (meters) | v (meters/sec) |
| 15 | ? |
| 40 | ? |
| ? | 17.1 |
| 5 | ? |
| ? | 19.8 |
| ? | 0.0 |
| 25 | 22.1 |
| ? | 24.2 |
| ? | 9.9 |
| ? | 28.0 |
| 0 | ? |
2.
a) What is the velocity halfway to the bottom of “The Drop”, where h = 25?
b) What is the velocity at the bottom of the drop, where h = 0?
3. If you made the roller coaster twice as high, do you think the velocity at the bottom be twice as great? Explain your answer
