Two places

The distance to the places is 60 km. From place A a pedestrian came out at a speed of 4 km/h and at the same time a car drove against him from place B. What was the speed of the car if the pedestrian met him in 90 minutes?

Correct result:

v =  36 km/h

Solution:

$$\begin{gathered} s=60\text{ km } \\ {v}_1=4\text{ km/h } \\ t=90\text{ min}\to \text{ h}=90\mathrm{/}60\text{ h}=1.5\text{ h } \\ s=v_1\cdot t+v\cdot t \\ 60=4\cdot 1.5+v\cdot 1.5 \\ 1.5v=54 \\ v=36=36\text{ km/h} \end{gathered}$$

Try another example

Showing 0 comments:

Next similar math problems:

• Motion 2
  At 10 o'clock started from place A car speed at 90 km/h. 20 minutes after started from the place B at speed 60 km/h another car. Distance places A and B is 120 kilometers. What time and where they meet?
• Cars motion
  From point A car start at the speed of 90 km/h. Against it departs from the point B at the same time another car at 60 km/h. For how long and where they met if the distance between A and B is 180 km?
• Cars speeds
  Distance from city A to city B is 108 km. Two cars were simultaneously started from both places. The speed of a car coming from city A was 2 km/h higher than the second car. What was the speed of each car if they met in 54 minutes?
• Pedestrian
  Pedestrian came started at 8h in the morning with speed 4.4 km/h. At half-past eleven cyclist started at 26 km/h same way. How many minutes take cyclist to catch up pedestrian?
• Grandmother
  Mom walked out to visit her grandmother in a neighboring village 5km away and moved at a speed of 4km/h. An hour later, father drove down the same road at an average speed of 64km/h. 1) How long will take to catch mom die? 2) What is the approximate dista
• Average speed
  Michal went out of the house by car at speed 98 km/h. He came into the goal place for 270 minutes. Determine the distance between the two places.
• Car and motorcyclist
  A car and a motorcyclist rode against each other from a distance of 190 km. The car drove 10km/h higher than the motorcyclist and started half an hour later. It met a motorcyclist in an hour and thirty minutes. Determine their speeds.
• Two trucks
  Two trucks left cities A and B against each other and met after an hour. The first car came to B 27 minutes later than the second car to A. Calculate the car speed if the distance between cities A, B is 90 km.
• Two aircraft
  Two planes fly to the airport. At some point, the first airplane is away from the airport 98 km and the second 138 km. The first aircraft flies at an average speed of 420 km/h, the second average speed is 360 km/h, while the tracks of both planes are perp
• Pedestrian and the cyclist
  Pedestrian and cyclist went against each from the two cities that are distant 40 km. Pedestrian started 30 minutes before the cyclist and walk an average speed of 5 km/h. What speed went cyclist when met after 120 minutes from the start of the pedestrian?
• Pedestrian and cyclist
  Pedestrian out with a speed of 4 km/hour from city center and after 1hour and 10 minutes came after him cyclist at speed of 18 km/h. At how many minutes he catches up with pedestrian?
• Truck
  In 7 hours started from town Krnov truck at speed 40 km/h. Passenger car started against it in 8 hours 30 minutes from the city of Jihlava at speed 70 km/h. Distance between this two cities is 225 km. At what time and at what distance from Krnov this two
• Car
  The car goes from point A to point B at speed 86 km/h and back 53 km/h. If it goes there and back at speed 67 km/h trip would take 10 minutes shorter. What is the distance between points A and B?
• Truck PRG-BA
  Truck driving on highway from Prague to Bratislava at average speed of 72 km/h. At the moment when the truck passes 54 kilometer from Prague passenger car departs from Prague which travel to Bratislava at speed 90 km/h. When and where (at waht highway kil
• Failure
  Drivers of passenger cars have calculated that at a speed of 60 km/h arrives at destination within 40 minutes. After 20 km refrain five minutes due a technical failure. How fast must go the rest of the way to the finish came at the scheduled time?
• Two trains
  Two trains go at each other. First at speed 40 km/h and the second at speed 60 km/h. At what distance will be 30 minutes before they will meet?
• Two cities
  The car goes from city A to city B at an average speed of 70 km/h, back at an average speed of 50 km/h. If it goes to B and back at an average speed of 60 km/h, the whole ride would take 8 minutes less. What is the distance between cities A and B?