Calculating Bus Meeting Time
This problem involves calculating the time it takes for two objects moving towards each other to meet. We are given the total distance separating them and their individual speeds.
Finding Relative Speed
When two objects move towards each other, their speeds add up to determine how quickly the distance between them closes. This is called their relative speed.
- Speed of Bus 1: \( v_1 = 20 \) km/hr
- Speed of Bus 2: \( v_2 = 18 \) km/hr
- Relative Speed: \( v_{rel} = v_1 + v_2 \)
Calculating the relative speed:
\( v_{rel} = 20 \text{ km/hr} + 18 \text{ km/hr} = 38 \text{ km/hr} \)
Calculating Time to Meet
The time it takes for the buses to meet is found by dividing the total distance between them by their relative speed.
- Distance: \( d = 76 \) km
- Relative Speed: \( v_{rel} = 38 \) km/hr
- Time = Distance / Relative Speed
Calculating the time:
\( t = \frac{d}{v_{rel}} = \frac{76 \text{ km}}{38 \text{ km/hr}} \)
\( t = 2 \) hours
Therefore, the buses will meet each other after 2 hours.
Important Questions from Partial Speed
A train having length 210 metres takes 25 seconds to cross a 540 metres long bridge. How much time will the train take to cross a 630 metres long bridge?
A person X from a place A and another person Y from a place B set out at the same time to walk towards each other. The places are separated by a distance of 15 km. X walks with a uniform speed of 1.5 km / hr and Y walks with a uniform speed of 1 km / hr in the first hour, with a uniform speed of 1.25 km / hr in the second hour and with a uniform speed of 1.5 km / hr in the third hour and so on.
Which of the following is / are correct?
1. They take 5 hours to meet.
2. They meet midway between A and B.
Select the correct answer using the code given below:
The speed of a train is 120 kmph. What is the distance covered by it in 15 minutes?
I walk a certain distance and ride back taking a total time of 37 minutes. I could walk both ways in 55 minutes. How long would it take me to ride both ways ?
Karan had covered two third of a certain distance when his car had a breakdown. He parked it and covered the remaining distance on foot. His time of travel on foot was 9 times his time of travel on car. What is the ratio of his walking speed with respect to his car’s speed?
