## Jason Running

## Opening

# Jason Running

Watch the video and think about the following questions.

- What two quantities in this video can be measured?
- How does the double number line track the relationship between the quantities?

VIDEO: Jason Running

Watch the video and think about the following questions.

- What two quantities in this video can be measured?
- How does the double number line track the relationship between the quantities?

VIDEO: Jason Running

Explain how to use Jason’s speed to find how long it takes him to go any distance.

Jason runs at a constant speed of 5 meters per second.

- How much time does it take Jason to run 240 meters?
- How many meters can Jason run in 55 seconds?
- Include the following in your answers:
- An estimate of what you think the answers might be
- The quantities involved in the problem
- A diagram, table, double number line, or other representation that shows why your solution makes sense
- Your equations, your work, and your solutions
- Two complete sentences that answer the questions

Multiply the rate 5 meters per second by the amount of time to find the distance traveled. For example, to find the distance traveled in 20 seconds, multiply 5 meters per second by 20 seconds:

20 seconds • 5 meters/second = 100 meters

Prepare a presentation about your method for solving the problem.

- Explain what you did differently to find the time compared with finding the distance.
- Use your work to support your explanation.

At the 1996 Olympics, Michael Duane Johnson set world records for the 200-meter and 400-meter races. He ran the 200-meter race in 19.32 seconds and the 400-meter race in 43.49 seconds.

- Calculate his speed for each race using a rate.
- In which race did he have the fastest speed? Justify your thinking.

- Take notes during the class discussion about how to solve for both distance and time.
- Answer questions about the methods you used to solve the problem.

As your classmates present, ask questions such as:

- Where do you see the rate 5 meters per second in your methods? Where do you see the answer?
- What operation did you use and why?
- Can you explain your solution in terms of the unit: what are the units of the rate, and how did the seconds cancel out?

Emma walked 3 miles in 60 minutes.

- What was her walking speed in terms of a rate?
- If she walks 4.5 miles at the same rate, how long will she walk?
- If she walks for 15 minutes at the same rate, how far will she walk?
- Make a double number line to show the relationships between the numbers.

- What are the quantities in the situation?
- How can you find the walking speed in terms of a rate?
- Did you use the expression
*d*=*rt*to help you solve for time or distance?

Summarize the mathematics of speed and how speed relates to rate.

Check your summary:

- Does your summary explain what
*speed*means, and does it give an example? - Does your summary include the term
*rate*? - Does your summary show the relationship among speed, distance, and time in three different ways?

Write a reflection about the ideas discussed in class today. Use the sentence starter below if you find it to be helpful.

**Something I learned about speed that really helps me solve problems is …**