Question

Помогите плиз! Решите задачи: a) Два велосипедиста выехали из городов А и Б, расстояние между которыми 420 км в противоположных направлениях. Велосипедисты ехали 4 часа и расстояние между ними стало 584 км. Какова скорость второго из велосипедистов, если скорость первого 20 км\ч. б) Два велосипедиста выехали из городов А и Б в противоположных направлениях. Велосипедисты ехали 4 часа и расстояние между ними стало 844 км. Каково расстояние между городами, если скорость первого 21 км\ч, а скорость второго - 22 км\ч. в) Два велосипедиста выехали из городов А и Б, расстояние между которыми 1260 км в противоположных направлениях. Через некоторое время расстояние между велосипедистами стало 1408 км. Какого время поездки, если скорость первого 19 км\ч, а скорость второго 18 км\ч.

Answer 1

А) 1) 20•4=80 (км) - проехал первый
2) 548-420=128 (км) - проехали оба
3) 128-80=48 (км) - проехал второй
4) 48:4=12 (км/ч)
Ответ: второй велосипедист ехал со скоростью 12 км/ч

б) 1) (21+22)•4=132 (км) - проехали оба
2) 844-132=712 (км)
Ответ: между городами 712 км

в) 1) 19+18=37 (км/ч) - общая скорость
2) 1408-1260=148 (км) - они проехали
3) 148:37=4 (ч)
Ответ: они ехали 4 часа

Answer 2

Task a)

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

Let's denote the speed of the second cyclist as v2 and the time they traveled as t.

Given that the first cyclist traveled at a speed of 20 km/h for 4 hours, the distance covered by the first cyclist is:

distance1 = speed1 × time1 = 20 km/h × 4 h = 80 km.

The total distance between the two cyclists is the sum of the distances covered by each cyclist:

distance1 + distance2 = 584 km.

Substituting the values we have:

80 km + distance2 = 584 km.

Simplifying the equation:

distance2 = 584 km - 80 km = 504 km.

Now we can use the formula to find the speed of the second cyclist:

distance2 = speed2 × time.

Substituting the values we have:

504 km = v2 × 4 h.

Simplifying the equation:

v2 = 504 km / 4 h = 126 km/h.

Therefore, the speed of the second cyclist is 126 km/h.

Task b)

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

Let's denote the distance between the two cities as d.

Given that the first cyclist traveled at a speed of 21 km/h for 4 hours, the distance covered by the first cyclist is:

distance1 = speed1 × time1 = 21 km/h × 4 h = 84 km.

The total distance between the two cyclists is the sum of the distances covered by each cyclist:

distance1 + distance2 = 844 km.

Substituting the values we have:

84 km + distance2 = 844 km.

Simplifying the equation:

distance2 = 844 km - 84 km = 760 km.

Therefore, the distance between the two cities is 760 km.

Task c)

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

Let's denote the time of the trip as t.

Given that the first cyclist traveled at a speed of 19 km/h and the second cyclist traveled at a speed of 18 km/h, the distance covered by each cyclist can be calculated as follows:

Distance covered by the first cyclist: distance1 = speed1 × time = 19 km/h × t.

Distance covered by the second cyclist: distance2 = speed2 × time = 18 km/h × t.

The total distance between the two cyclists is the sum of the distances covered by each cyclist:

distance1 + distance2 = 1408 km.

Substituting the values we have:

19 km/h × t + 18 km/h × t = 1408 km.

Simplifying the equation:

37 km/h × t = 1408 km.

Solving for t:

t = 1408 km / 37 km/h ≈ 38.05 hours.

Therefore, the time of the trip is approximately 38.05 hours.

Please let me know if you need any further assistance!