a round trip car ride took 12 hours. the first half of the trip took 7 hours at a rate of 4 miles per hour. what was the average rate of speed on the return trip?
how do i write this as an equation?
distance = rate * time
The distance for both directions are equal.
rate1 * time1 = rate2 * time2
I think its 63 miles per hour.
How i got it:
12 hrs. minus 7 hrs. = 5hrs for the return trip.
45*7= r*5
315==r*5
315/5 = 63 miles per hour
(i think that 63 is the answer. im not sure)
To write this as an equation, let's first define the variables. Let "x" represent the speed on the return trip in miles per hour.
Now, let's calculate the distance of the entire trip. Since the first half of the trip took 7 hours at a rate of 4 miles per hour, the distance covered in the first half is calculated as 7 hours multiplied by 4 miles per hour, which equals 28 miles.
Since it is a round trip, the entire journey covers the same total distance. Therefore, the distance of the return trip is also 28 miles.
To calculate the time taken for the return trip, we can subtract the time taken for the first half (7 hours) from the total trip time (12 hours). So, the time taken for the return trip is 12 hours minus 7 hours, which equals 5 hours.
Now we can set up the equation:
Distance = Speed x Time
For the return trip, the distance is 28 miles, the speed is "x" miles per hour, and the time is 5 hours. So the equation becomes:
28 = x * 5
Simplifying the equation, divide both sides by 5:
28/5 = x
Therefore, the equation is: x = 5.6
Hence, the average rate of speed on the return trip is 5.6 miles per hour.