Answer to Question #4583 in Mechanics | Relativity for anjali sharma
A, B and C participated in a race around a circular track. A and B run in the same direction while C runs in the opposite direction. If the speeds of A, B and C are 10 m/s, 20 m/s and 30 m/s respectively, and the length of the track is 1000m, then after how long will they take to meet for the first time 125 seconds 100 seconds 200 seconds 150 seconds
Let T be the time they'll meet for the first time. So, the distance A,B and C will run before meeting is 10T, 20T and 30T, respectively. The only place they can meet at is the start point. So, T must satisfy these conditions: 1000a = 10T, 1000b = 20T, 1000c = 30T, where a,b,c are the number of laps A, B and C have to take before they met. We see that the minimum time to satisfy this condition is 100 seconds. By this time, A, B and C will take 1, 2 and 3 laps respectively.