8. Sylvia is training for a triathlon. she cycles 6.25 km in 25 min.
a) What is her average speed, in kilometres per hour?
b) Solve a proportion to determine how long she would take to cycle 40 km. Us the speed in part A)
math is bad
6.25 km x 2.4 = 15 km
25 mins x 2.4 = 1 hour
so her average speed is 15km per hour
6.25\ 25=15
a) Ah, Sylvia, the triathlon superstar! Let's calculate her average speed with the given information. We know she cycled 6.25 km in 25 min. So, to find her average speed, we divide the distance by the time taken: 6.25 km ÷ 25 min = 0.25 km/min.
Now, we need to convert this speed into kilometers per hour. Since there are 60 minutes in 1 hour, let's multiply the speed by 60: 0.25 km/min x 60 min/hour = 15 km/hour. Voila!
So, Sylvia's average speed is 15 kilometers per hour.
b) Now, let's work on determining how long it would take Sylvia to cycle 40 km, using the speed we found in part a).
To solve this proportion, we set up the equation:
6.25 km / 25 min = 40 km / x min
Cross-multiplying, we get:
6.25 km * x min = 40 km * 25 min
Simplifying both sides:
(6.25 * x) km * min = (40 * 25) km * min
Dividing both sides by 6.25:
x = (40 * 25) km * min / 6.25 km
x = 1000 min / 6.25
x = 160 min
So, it would take Sylvia approximately 160 minutes to cycle 40 km at her average speed. Keep pedaling, Sylvia!
To answer these questions, we need to understand the relationship between average speed, distance, and time. The formula for average speed is:
Average Speed = Distance / Time
a) To find Sylvia's average speed in kilometers per hour, we need to convert the time from minutes to hours. There are 60 minutes in one hour. So, to convert minutes to hours, we divide the time value by 60:
Time (in hours) = 25 min / 60 = 0.4167 hours (rounded to four decimal places)
Now we can calculate average speed:
Average Speed = Distance / Time
Average Speed = 6.25 km / 0.4167 hours
Average Speed ≈ 15 km/h (rounded to the nearest whole number)
Therefore, Sylvia's average speed is approximately 15 kilometers per hour.
b) Now let's solve a proportion to determine how long it would take her to cycle 40 kilometers, using the average speed calculated in part a).
Proportion:
Distance 1 / Time 1 = Distance 2 / Time 2
Let's substitute the values we know:
6.25 km / 0.4167 hours = 40 km / Time 2
Now we can solve for Time 2:
40 km / Time 2 = (6.25 km / 0.4167 hours)
Cross-multiplying:
40 km * 0.4167 hours = 6.25 km * Time 2
16.668 hours * Time 2 = 6.25 km
Divide both sides by 16.668 to solve for Time 2:
Time 2 ≈ 0.3744 hours (rounded to four decimal places)
Now, convert the time back to minutes:
Time 2 (in minutes) = 0.3744 hours * 60 = 22.44 minutes (rounded to two decimal places)
Therefore, it would take Sylvia approximately 22.44 minutes to cycle 40 kilometers at her average speed.
a. avg speed= distance/time=6.25km/(25/60)
B. 40/SPEEDABOVE= (25/60*TIME)
TIME=25/(60*40) * SPEEDABOVE