Please help me? A motorist takes a trip of 100 miles, traveling at 40 mph for the first 50 miles and 60 mph for the last 50 miles. What is the average speed in mph for the trip? The answer is not 50 mph.
distance = rate x time
Calculate time for each 50 mile increment. Add the times together to obtain total time.
then 100/total time = average rate. Post your work if you get stuck.
i can't figure it out???
distance = rate x time
d for 40 mph vehicle = 50 mi = 40 mi/hr x time.
solve for time for 40 mph car = 50/40 = 5/4 hour.
d for 60 mph car = 50 mi = 60 mi/hr x t
solve for t for 60 mph car = 50/60 = 5/6 hr.
Add the times together.
5/4 + 5/6 = 1.250 + 0.833 = 2.083 hours total time.
distance traveled in total time = 100 miles. Average speed = 100 mi/2.083 hours = ??
To find the average speed for the entire trip, you can use the formula:
Average Speed = Total Distance / Total Time
First, we need to calculate the total distance traveled. In this case, the motorist traveled 50 miles at 40 mph, and another 50 miles at 60 mph. So the total distance is 100 miles.
Next, we need to calculate the total time it took to travel the entire distance. To do this, we can calculate the time taken for each part of the trip and then add them together.
For the first 50 miles traveled at 40 mph, we can calculate the time as follows:
Time = Distance / Speed = 50 miles / 40 mph = 1.25 hours
For the second 50 miles traveled at 60 mph, we can calculate the time as follows:
Time = Distance / Speed = 50 miles / 60 mph = 0.83 hours
Now, we can find the total time taken for the entire trip by adding the times for the two legs of the trip:
Total Time = 1.25 hours + 0.83 hours = 2.08 hours
Finally, we can calculate the average speed by dividing the total distance by the total time:
Average Speed = Total Distance / Total Time = 100 miles / 2.08 hours ≈ 48.08 mph
So, the average speed for the entire trip is approximately 48.08 mph, not 50 mph.