Fog

The car started in fog at speed 30 km/h. After a 12-minute drive, the fog dissipated and the driver drove next 12 minutes distance 17 km. On the last 17 km long again the driving conditions deteriorated and the driver drove the speed of 51 km/h.

a) Calculate the distance of the first section, the speed on the second section and the time on third section.
b) Construct the graph distance vs. time t.
c) Calculate the average speed for the first two sections and the average speed on the last two sections. When can the average rate calculated as the arithmetic mean of the individual speeds? Judge answer.

Correct answer:

s1 =  6 km
v2 =  85 km/h
t3 =  0.3333 h
c1 =  57.5 km/h
c2 =  63.75 km/h

Step-by-step explanation:

s1=30 12/60=6 km
v2=17/(12/60)=85 km/h
t3=17/51=0.3333 h
c1=(s1+17)/((12+12)/60)=1152 km/h=57.5 km/h
c2=(17+17)/(12/60+t3)=2554 km/h=63.75 km/h



We will be pleased if You send us any improvements to this math problem. Thank you!






avatar




Tips to related online calculators
Looking for help with calculating arithmetic mean?
Looking for a statistical calculator?
Do you want to convert velocity (speed) units?
Do you want to convert time units like minutes to seconds?

 
We encourage you to watch this tutorial video on this math problem: video1

Related math problems and questions:

  • Constant motion
    car The car has undergone constant motion 120 km in 1 hour 30 minutes. Determine its average speed. Determine how long car drove in the first 20 minutes and 50 minutes from the start of the move.
  • Znojmo
    car From Znojmo to Brno started truck with a trailer at an average speed 53 km per hour. Against him 14 minutes later from Brno started car with an average speed of 1.2-times greater than the truck. How long and how far from Znojmo, they meet if the distance
  • Car driver
    cars The car driver is in town A and is scheduled to be in town B at a specified hour. If it travels at an average speed of 50km/h, it will arrive in city B 30 minutes later. But if he travels at an average speed of 70km/h, he would arrive half an hour earlier
  • Two cities
    cyclist The distance between cities A and B is 132 km. At 9.00 am, the cyclist started the bike at an average speed of 24 km/h, and at 10.00 am started from the B cyclist at an average speed of 30 km/h. How long and far from A will they both meet?
  • Driver
    truck The driver of the supply car reckoned that at the average speed of 72 km/h arrives to the warehouse for 1 1/4 hours. After 30 km however unintentionally drove to the gas station and have ten minutes delay. At what average speed would have to go the rest o
  • Motion 2
    motion2 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?
  • Motion
    bus From two different locations distant 232 km started against car and bus. The car started at 5:20 with average speed 64 km/h. Bus started at 7:30 with average speed 80 km/h. When they meet? How many kilometers went the bus?
  • Two cities
    cars 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?
  • Average speed
    speed The car drove on one section of the highway for half an hour at a speed of 80 km/h. Then he reduced his speed to 60km/h. It went three-quarters of an hour at a speed of 60 km/h. What was the average speed of the car?
  • Cars speeds
    cars 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?
  • Two cars
    cars_racing Two cars started against each other at the same time to journey long 346 km. The first car went 53 km/h and the second 53 km/h. What distance will be between these cars 20 minutes before meet?
  • Cars 2
    car Opava is 360 km distance from Prešov. At 8:00 hour, two cars started against each other from this cities at average speeds 88 km/h and 121 km/h. What hour will it meet and what distance it's travel if the car started from Prešov is faster?
  • Car and motorcyclist
    car 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.
  • Car and cyclist
    cyclist Cyclist started from town at a speed of 18 km/h. After 1 hour 30 min started the car from town and caught up with the cyclist in 50 minutes. How fast was a car?
  • Car
    city The driver of a car is to get to 608 km distant city. From atlas found that 162 km will have to pass through the cities at average speed 48 km/h. Remainder of the journey pass outside the cities at average speed 116 km/h. Calculate how many hours it will
  • The car
    cars The car has traveled the distance between A and B for four hour. If we increased the average by 17 km/h the car travel this distance an hour earlier. Determine the initial speed of the car and the distance between A and B.
  • Where and when
    cars The truck left Kremnica at 11:00 h at a speed of 60km/h. At 12:30 h, the passenger car started at an average speed of 80km/h. How many kilometers from Kremnica will the passenger car reach truck, and when?