0
What if your average speed on the first half of a car trip is 67 km per hour How fast do you have to drive on the second half of the trip to achieve an average speed of 86 km per ho for the whole trip?
Wiki User
∙ 14y ago
Length of the whole trip = D km
Unknown speed for the second half = X km/hr
Time for the first half = (D/2)/67 = D/134 hours
Time for the second half = (D/2)/x = D/(2x) hours
Total time for the trip = (D/134) + (D/2x) = D/86
1/134 + 1/2x = 1/86
2x/134 + 1 = 2x/86
x/67 + 1 = x/43
x(1/43 - 1/67) = 1
x = 1 / (1/43 - 1/67) = (43 x 67) / (67 - 43) = 2881/24 = 120.042 km/hr (rounded)
=============================================
Check:
(1/134) + (1/240.084) = (240.084 + 134) / (240.084 x 134) = 1/86 QED yay !
Wiki User
∙ 14y ago
Add your answer:
Earn +20 pts
What does running average of all grades mean?
The first running average is the first grade. The second running average (RA) is the average of the first two grades, the third RA is the average of the first three grades and so on.
Average walking distance in a day?
Lucy's family drove 463 km on the first day and 421 on the second day. What was the average distance in a day
What grade should you know my 3 times tables?
On average u should know them in first or second grade !
He average of a number is 34 the first number is three times the second numberwhat are the two numbers?
Simply divide 34 by 4 and you get 8.5, which is the second number and the first number must be three times 8.5, which is 25.5
What is average of 10 6 12?
Calculating an average is done in two steps: - First: you calculate the sum of the terms whose average you would like to calculate. - Second: you divide the sum of the terms by their number. In your case: - First: 10 + 6 + 12 = 28 - Second: 28 / 3 = 9.33333.... 3 is the number of terms added together which are: 10, 6 and 12 (3 numbers). Answer: Therefore your average is: 9.33333....
Who was the second person to achieve flight?
Nobody knows for sure who was even the FIRST to achieve flight.
What is B drive in computer system?
Normally the second removable drive, A = first removable or floppy drive, if a second floppy drive is installed it is drive B. First hard disk is Drive C, second Hard disk is Drive D, etc. You can also map the drive letters to the virtual network connections, so that Drive P could be used as a network connection.
What does the second drive axle do in a tandem drive truck?
The exact same thing as the first drive axle.
My first semester comulative average is 85 how do they calculate the average of second semester?
The second semester cumulative average will be calculated by the number of units in your second semester.
What was Faber drive's first song?
Second Chance, Sex and Love and 24 Story were Faber Drive's first songs.
What is the average acceleration south?
what do you mean you cant just drive the south around first off it dont have wheels second where you gonna get enough gas for the whole south
How do you over come your fears of cars?
second answer get help then drive one first answer Drive one!
If my first semester average was 85 how do they calculate the averae of the second semester with respect to the average of the first semester?
The final tally will be the average of your two semesters. Your second semester grade will only reflect your second semester units.
How do cut and paste to a flash drive?
Plug the first flash drive into a computer, copy the file into the computer, unplug the first flash drive, then plug the second into the computer, cut and paste the file from the computer to the second flash drive. The file is now on both flash drives.
Can you drive a second car i just bot on your first cars insurance?
no
What does running average of all grades mean?
The first running average is the first grade. The second running average (RA) is the average of the first two grades, the third RA is the average of the first three grades and so on.
What is the average age to purchase a first car?
16 because that's the average age to be able to drive.
