Final answer:
Elsa swims 4 laps, where each lap is back and forth across the pool. To find the total distance, we multiply the distance of one way across the pool by 8. Additionally, the distance to the other end of a pool, with waves traveling at 0.750 m/s and reflecting in 30 seconds, can be found using the formula for wave speed and time.
Step-by-step explanation:
Elsa swims 4 laps of backstroke for a race. If a lap consists of going down the pool and coming back, we want to find out the total distance she swims, not counting the turns.
Let d be the distance of one way across the pool. Therefore, one lap will be 2d (down and back).
The equation to find the total distance for 4 laps would then be:
Total distance = number of laps × distance per lap
We can write the equation as:
Total distance = 4 × 2d
Once we know the length of the pool one way (d), we multiply by 8 to get the total distance Elsa swims.
When waves in a swimming pool propagate at a speed of 0.750 m/s and it takes 30 seconds for them to go to the other end of the pool, reflect, and return, we can find the distance to the other end using the equation:
Distance to other end = (speed of wave × total time for round trip) / 2
Plugging in the values, we have:
Distance to other end = (0.750 m/s × 30.0 s) / 2
= 11.25 m