Question

Сестра и брат вышли из дома в разные стороны через 0,15 часа расстояние между ними было 1,3 км Найдите скорость с которой шёл брат, если сестра шла со скоростью 4,5 км\ч

Answer 1

Скорость брата обозначим за хкм/ч, тогда общая скорость удаления брата и сестры равна( х + 4,5 )км/ч. Время и расстояние известно, составим уравнение: 
15 мин = 15/60часа = 0, 25часа.
( х+4,5)* 0,25 = 1,3
0,25х + 1,125 = 1,3
0,25х = 1,3 - 1,125 
0,25х = 0,175
х = 0,175 : 0,25
х =0,7
Ответ: Брат шел со скоростью 0,7 км/ч.

Answer 2

Problem Analysis

We are given that a sister and a brother leave home in different directions. After 0.15 hours, the distance between them is 1.3 km. We need to find the speed at which the brother is walking, given that the sister is walking at a speed of 4.5 km/h.

Solution

To find the brother's speed, we can use the formula:

Speed = Distance / Time

We know the distance between the sister and brother after 0.15 hours is 1.3 km. Let's calculate the brother's speed.

Distance = 1.3 km

Time = 0.15 hours

Speed = Distance / Time

Speed = 1.3 km / 0.15 hours

Calculating the above expression will give us the brother's speed.

Calculation

Let's calculate the brother's speed using the given values.

Speed = 1.3 km / 0.15 hours

Speed ≈ 8.67 km/h

Therefore, the brother's speed is approximately 8.67 km/h.

Answer

The brother was walking at a speed of approximately 8.67 km/h.

Note: The answer has been calculated based on the given information and the formula for speed.