Two motorcyclists left the settlements M and N, 50 km apart from each other, and met in 30 minutes.
Two motorcyclists left the settlements M and N, 50 km apart from each other, and met in 30 minutes. Find the speed of each motorcyclist if it is known that one of them arrived at point M 25 minutes earlier than the other from point N. P.S If not difficult, outline this problem schematically so that in the future I understand how these problems are solved.
Since the meeting took place after 30 minutes (1/2 hour), the speed of convergence was:
50: 1/2 = 100 km / h.
Let’s take the speed of motorcyclists for x and y, since they were moving towards each other, the speed of approach is the sum of their speeds:
x + y = 100.
50 / x – travel time of the first;
50 / y – second.
Second equation:
50 / x – 50 / y = 25/60.
1 / x – 1 / y = 1/120.
From the first:
x = 100 – y.
Let’s substitute in the second:
1 / (100 – y) – 1 / y = 1/120;
y – (100 – y) = 1/120 * y * (100 – y);
y ^ 2 – 20y – 1200 = 0.
y = 48;
x = 52.