A and B run around a circular track whose cicumference is 150m. when they run is opposite directions they meet every 5 seconds, but when they run in the same direction from the some point they are together every 25 seconds. what are their rates? ans. 18m/s and 12m/s
can you help me on why it ended up with 18m/s and 12m/s as an answer pleaseee
5v₁+5v₂=150
25v₁-25v₂=150
v₁+v₂=30
v₁-v₂=6
v₁=18 m/s
v₂ = 12 m/s
Hey Natalie,
So what is happening in part A where they are running in opposite directions is that the sum of their velocities (18+12=30 m/s) is what causing them to meet, because every second 30 meters are covered. So in 5 seconds 150 meters are covered in total, meaning the entire circumference has been ran and they meet.
In part two its the opposite, we take the difference of the velocities (18-12=6m/s) so as every second passes the slower of the two is 6 meters behind the other. So in 25 seconds (25*6=150) the slower will be 150 meters behind the faster of the two, and the faster will be 150 meters ahead of the slower of the two, AND the circumference of the circle is 150 meters so they will meet again on the circle.
I hope that helps I tried to take it as slow as possible there.
Can you please make a solution for this problem so i could understand it better...
Sure, I can help you understand how we ended up with the rates of 18m/s and 12m/s as the answer.
Let's represent the speeds of A and B as VA and VB respectively.
When they run in opposite directions and meet every 5 seconds, it means that in 5 seconds, they cover the distance of the entire circumference of the track, which is 150m. So, the relative speed when they are running in opposite directions is the sum of their individual speeds.
Hence, VA + VB = 150m/5s = 30m/s. (Equation 1)
When they run in the same direction, they are together every 25 seconds. This means that in 25 seconds, the faster runner (let's assume it is A) covers the entire track while the slower runner (B) covers a certain distance.
Since A covers the entire track, VA = 150m/25s = 6m/s. (Equation 2)
Now, the distance covered by B in 25 seconds is the difference between the distance of the entire track and the distance covered by A. So, the distance covered by B is 150m - distance covered by A = 150m - (VA * 25s).
Therefore, VB = (150m - 6m/s * 25s)/25s = (150m - 150m)/25s = 0m/s. (Equation 3)
From Equation 1, we have VA + VB = 30m/s. Plugging in the value of VB from Equation 3, we get VA + 0m/s = 30m/s, which simplifies to VA = 30m/s.
Therefore, the speed of A, VA, is 30m/s and the speed of B, VB, is 0m/s.
Please keep in mind that these speeds are for relative motions, meaning the speeds of A and B with respect to each other. They do not represent their actual speeds in absolute terms.
I hope that clarifies how we arrived at the speeds of 18m/s and 12m/s for A and B!
To solve this problem, we need to apply the concepts of relative motion and the relationship between speed, time, and distance.
Let's assume the speeds of A and B as v₁ and v₂, respectively. When they run in opposite directions, the relative speed between them is the sum of their individual speeds. So, the equation based on distance would be:
(v₁ + v₂) × 5 seconds = 150 meters
When they run in the same direction, the relative speed is the difference between their speeds. The equation based on distance would be:
(v₁ - v₂) × 25 seconds = 150 meters
Now, we have a system of two equations with two unknowns (v₁ and v₂). We can solve it to find their speeds.
Let's solve the first equation for v₁ + v₂:
(v₁ + v₂) × 5 = 150
Divide both sides by 5:
v₁ + v₂ = 30
Similarly, let's solve the second equation for v₁ - v₂:
(v₁ - v₂) × 25 = 150
Divide both sides by 25:
v₁ - v₂ = 6
Now, we have a system of equations:
v₁ + v₂ = 30 ----(1)
v₁ - v₂ = 6 ----(2)
To solve this system, we can add equations (1) and (2):
(v₁ + v₂) + (v₁ - v₂) = 30 + 6
2v₁ = 36
Divide both sides by 2:
v₁ = 18
Now, substitute the value of v₁ in equation (1) to find v₂:
18 + v₂ = 30
v₂ = 30 - 18
v₂ = 12
Thus, the speed of A is 18 m/s and the speed of B is 12 m/s.