Question

От автобусной остановки одновременно в одном направлении отъехали автобус и велосепедист.Скорость автобуса равна 45 км/ч , а велосепедиста 15 км/ч.Через какое время расстояние между ними будет 12 км

Answer 1

U1 - 45
U2 - 15
S - 12
t = 45 + 15 : 12 = 4ч

Answer 2

Problem Analysis

We are given that a bus and a cyclist start simultaneously from a bus stop in the same direction. The speed of the bus is 45 km/h, and the speed of the cyclist is 15 km/h. We need to determine the time it takes for the distance between them to be 12 km.

Solution

To solve this problem, we can use the formula: distance = speed × time.

Let's assume that the time it takes for the distance between the bus and the cyclist to be 12 km is t.

The distance traveled by the bus in time t is given by: distance_bus = speed_bus × t.

The distance traveled by the cyclist in time t is given by: distance_cyclist = speed_cyclist × t.

Since they start simultaneously from the same point, the distance traveled by the bus and the cyclist should be equal to the distance between them, which is 12 km.

Therefore, we can set up the following equation:

distance_bus = distance_cyclist

speed_bus × t = speed_cyclist × t

Simplifying the equation, we get:

45t = 15t

Dividing both sides of the equation by 15, we get:

3t = t

This equation implies that t = 0.

However, this result doesn't make sense because it means that the distance between the bus and the cyclist is 0, which contradicts the given information that the distance between them is 12 km.

Therefore, there is no solution to this problem.

Conclusion

The time it takes for the distance between the bus and the cyclist to be 12 km is undefined. There is no solution to this problem because the bus and the cyclist have different speeds, and the distance between them will continue to increase indefinitely.