Motion problem

From Levíc to Košíc go car at speed 81 km/h.
From Košíc to Levíc go another car at speed 69 km/h.

How many minutes before the meeting will be cars 27 km away?

Result

t =  10.8 min

Solution:

$v_{ 1 } = 81 \ km/h \ \\ v_{ 2 } = 69 \ km/h \ \\ s = 27 \ km \ \\ \ \\ v = v_{ 1 }+v_{ 2 } = 81+69 = 150 \ km/h \ \\ t_{ 1 } = \dfrac{ s }{ v } = \dfrac{ 27 }{ 150 } = \dfrac{ 9 }{ 50 } = 0.18 \ h \ \\ t = t_{ 1 } \rightarrow h = t_{ 1 } \cdot \ 60 \ h = 10.8 \ h = \dfrac{ 54 }{ 5 } = 10.8 \ \text { min }$

Leave us a comment of this math problem and its solution (i.e. if it is still somewhat unclear...):

Be the first to comment!

Following knowledge from mathematics are needed to solve this word math problem:

Need help calculate sum, simplify or multiply fractions? Try our fraction calculator. Do you have a linear equation or system of equations and looking for its solution? Or do you have quadratic equation? Do you want to convert length units?

Next similar math problems:

1. Cottage house
The village is 28 km from the cottage. Father goes from village to cottage. Son goes from the cottage to the village. They meet 10 km further behind the cottage. How much did dad walk?
2. Car loop
The toy car runs at an average speed of 2 m/s. In a minute, it will pass the entire circuit five times. How long is the loop?
3. An equilateral triangle
The perimeter of an equilateral triangle is 33cm. How long is each side?
Calculate the radius of the circle whose length is 107 cm larger than its diameter
5. Squares
From a square of 12 dm perimeter is cut smaller square, whose side is the third side of the square. What is the area of the rest?
6. Athletic race
Before a race, you start 4 5/8 feet behind your friend. At the halfway point, you are 3 2/3 feet ahead of your friend. What is the change in distance between you and your friend from the beginning of the race?
7. 45th birthday
This year Mrs. Clever celebrated her 45th birthday. Her three children are now 7.11 and 15 years old. In how many years will Mrs. Clever's age be equal to the sum of her children's years?
8. Coal mine
The towing wheel has a diameter of 1.7 meters. How many meters does the elevator cage lower when the wheel turns 32 times?
9. Video game
Nicole is playing a video game where each round lasts 7/12 of an hour. She has scheduled 3 3/4 hours to play the game. How many rounds can Nicole play?
10. School trip
On a school trip, 17 of the 28 children bought ice cream or chocolate in a candy store. Twelve children bought chocolate, and nine children bought ice cream. How many children bought ice cream and chocolate? How many children did not buy ice cream? How man
11. Holidaymakers
A total of 94270 holidaymakers spent part of their holiday in 50 hotels a year. On average, how many vacationers are there for one hotel?
12. Almonds
Rudi has 4 cups of almonds. His trail mix recipe calls for 2/3 cup of almonds. How many batches of trail mix can he make?
13. Jared's room painting
Jared wants to paint his room. The dimensions of the room are 12 feet by 15 feet, and the walls are 9 feet high. There are two windows that measure 6 feet by 5 feet each. There are two doors, whose dimensions are 30 inches by 6 feet each. If a gallon of pa