Question

Автобус проехал 4км со средней скоростью 20км/ч следующие 12км проехал со средней скоростью 40км/ч .Какова средняя скорость автобуса за всё время движения?

Answer 1

V=S/t =(S₁+S₂)/(t₁+t₂) = (S₁+S₂)/[(S₁/V₁) +(S₂/V₂)]
V=(4+12)/[(4/20) +(12/40)] =16/0,5=32 км/ч

Answer 2

V=S1+S2
------
S1/V1 + S2/V2
16/0,2 = 80

Answer 3

Calculation of Average Speed

To calculate the average speed of the bus for the entire duration of the journey, we need to consider the distances traveled and the corresponding speeds.

The bus traveled 4 km with an average speed of 20 km/h, and then it traveled another 12 km with an average speed of 40 km/h.

To find the average speed, we can use the formula:

Average Speed = Total Distance / Total Time

Let's calculate the average speed step by step.

1. Calculate the total distance traveled by the bus: - The bus traveled 4 km initially. - Then it traveled another 12 km. - So, the total distance traveled by the bus is 4 km + 12 km = 16 km.

2. Calculate the total time taken by the bus: - To find the total time, we need to calculate the time taken for each segment of the journey. - The time taken for the first segment (4 km at 20 km/h) can be calculated using the formula: Time = Distance / Speed. - So, the time taken for the first segment is 4 km / 20 km/h = 0.2 hours. - The time taken for the second segment (12 km at 40 km/h) can be calculated in the same way: 12 km / 40 km/h = 0.3 hours. - Therefore, the total time taken by the bus is 0.2 hours + 0.3 hours = 0.5 hours.

3. Calculate the average speed: - Using the formula Average Speed = Total Distance / Total Time, we can substitute the values: Average Speed = 16 km / 0.5 hours = 32 km/h.

Therefore, the average speed of the bus for the entire duration of the journey is 32 km/h.