Question

Помогите срочно! Время поджимает! Автомобіль проїхав першу третину шляху із швидкістю 30 км/год, другу третину із швидкістю 40 км/год, а решту шляху із швидкістю 50 км/год. Яка середня швидкість автомобіля?

Answer 1

(S/3)/V1+(S/3)/V2+(S/3)/V3=S/V(cp)
1/(3*30)+1/(3*40)+1/(3*50)=1/V(cp)---->38.28 км/ч

Answer 2

Calculating the Average Speed of the Car

To calculate the average speed of the car, we can use the formula for average speed, which is the total distance traveled divided by the total time taken.

Let's denote: - \(d_1\) as the distance traveled at 30 km/h - \(d_2\) as the distance traveled at 40 km/h - \(d_3\) as the distance traveled at 50 km/h - \(t_1\) as the time taken to travel \(d_1\) - \(t_2\) as the time taken to travel \(d_2\) - \(t_3\) as the time taken to travel \(d_3\)

The total distance traveled is \(d_1 + d_2 + d_3\), and the total time taken is \(t_1 + t_2 + t_3\).

Calculating the Distances and Times

First, let's calculate the distances and times for each segment of the journey.

1. Distance traveled at 30 km/h: - Let's assume the total distance of the journey is \(d\) kilometers. - The distance traveled at 30 km/h is \(\frac{1}{3}d\) kilometers. - The time taken to travel this distance is \(\frac{\frac{1}{3}d}{30}\) hours.

2. Distance traveled at 40 km/h: - The distance traveled at 40 km/h is also \(\frac{1}{3}d\) kilometers. - The time taken to travel this distance is \(\frac{\frac{1}{3}d}{40}\) hours.

3. Distance traveled at 50 km/h: - The distance traveled at 50 km/h is \(\frac{1}{3}d\) kilometers. - The time taken to travel this distance is \(\frac{\frac{1}{3}d}{50}\) hours.

Calculating the Total Distance and Time

Now, let's calculate the total distance and time.

- Total distance, \(d\), is the sum of the distances traveled at each speed: \(d = \frac{1}{3}d + \frac{1}{3}d + \frac{1}{3}d = d\). - Total time, \(t\), is the sum of the times taken at each speed: \(t = \frac{\frac{1}{3}d}{30} + \frac{\frac{1}{3}d}{40} + \frac{\frac{1}{3}d}{50}\).

Calculating the Average Speed

Finally, we can calculate the average speed using the formula:

\[ \text{Average Speed} = \frac{\text{Total Distance}}{\text{Total Time}} \]

Let's proceed with these calculations.