a plane flew from red deer to winnipeg, flying distance of 1260 km. on the return journey, due to a strong head wind, the plane travelled 1200 km in the same time it took to complete the outward journey. on the outward journey, the plane be able to maintain an average speed 20km/hr greater than on the return journey.
if average speed of plane from red deer to winnipeg is xkm/hr, state an expression for the average speed of the plane from winnipeg to red deer in km/hr.
i wrote (x-20)km/hr
calculate average speed of the plane from winnipeg to red deer.
i also not real get how to do this. i go speed = distance/time?
calculate total flying time for round trip.
Time to W = 1260/x
Time back if had gone all the way = (1260/1200)* time to W = 1260^2/1200x
speed back =(x-20)
so
1260 = (x-20)(1260^2/1200x)
1200 x = (x-20)(1260)
1200 x = 1260 x - 20(1260)
60 x = 20(1260)
x = 420
x-20 = 400
thanks very much damon :)
To calculate the average speed of the plane from Winnipeg to Red Deer, you can subtract 20 km/hr from the average speed of the plane from Red Deer to Winnipeg (x km/hr). So, the expression for the average speed of the plane from Winnipeg to Red Deer is (x - 20) km/hr.
To calculate the average speed, you are correct that speed is equal to distance divided by time. In this case, the distance on the return journey is 1200 km (since it traveled this distance on the return journey) and the time it took to complete the outward journey is the same as the time it took to complete the return journey.
So, the average speed of the plane from Red Deer to Winnipeg is x km/hr and the distance is 1260 km. This gives us the equation:
x = 1260 / t (where t is the flying time)
For the return journey, the distance is 1200 km and the average speed is (x - 20) km/hr. This gives us the equation:
(x - 20) = 1200 / t
Since the time taken for both journeys is the same, we can set the two equations equal to each other and solve for t:
1260 / t = 1200 / t
1260 = 1200
t = 1260 / 1200
t = 1.05 hours
Therefore, the average speed of the plane from Winnipeg to Red Deer is (x - 20) km/hr. To calculate the total flying time for the round trip, we have the outward journey time of 1.05 hours and the return journey time, which is also 1.05 hours. So, the total flying time for the round trip is 1.05 + 1.05 = 2.1 hours.
To determine the average speed of the plane from Winnipeg to Red Deer, we need to take into account that it travels at a speed 20 km/hr slower than the average speed from Red Deer to Winnipeg (x km/hr).
So, the expression for the average speed of the plane from Winnipeg to Red Deer would be (x - 20) km/hr, as you correctly wrote.
To calculate the average speed, we can use the formula:
Average speed = total distance / total time.
To calculate the total flying time for the round trip, we need to find the individual times for the outward and return journeys.
Let's assume the time taken for the outward journey is t1 hours. Since we know that the distance for the outward journey is 1260 km, we can use the formula speed = distance / time to write:
x = 1260 km / t1
Now, for the return journey, we are given that it took the same amount of time as the outward journey (t1 hours) but covered a distance of 1200 km. We can again use the formula speed = distance / time to write:
(x - 20) = 1200 km / t1
To solve this system of equations, we can equate the two expressions for x:
1260/t1 = 1200/t1 + 20
Simplifying this equation, we get:
1260 = 1200 + 20t1
Subtracting 1200 from both sides:
60 = 20t1
Dividing both sides by 20:
t1 = 3 hours
Now that we know the time for the outward journey (t1), we can substitute it into the expression for the average speed from Winnipeg to Red Deer:
(x - 20) = 1200 km / 3 hours
(x - 20) = 400 km/hr
Therefore, the average speed of the plane from Winnipeg to Red Deer is 400 km/hr.
To calculate the total flying time for the round trip, we need to add the time for the outward journey (3 hours) and the time for the return journey (also 3 hours), giving us a total flying time of 6 hours.