A train left Podunk and traveled west at 70 km/h. Two hours later, another train left Podunk and traveled east at 90 km/h. How many hours had the first train traveled when they were 1420 km apart?
How do you solved this?
I translated your English into Math and got
70t+140 + 90t = 1420
Take it from there.
where did you get 140 from?
didn't the first train go for 2 hrs at 70 km/h ? How far did it go in that time ?
Got it. Thank you very much
Welcome!
a train left podunk and traveled north at 75 km/h. two hours later, another train left podunk and travled in the same direction at 100 km/h. how many hours had the first train traveled when the second train overtook it?
can someone help set this up?
8 hrs.....
aly, its not 8 hrs......
You would set them up equal to each other.
Looks like.
75T + 150 = 100T
T= 6
To solve this problem, you need to use the concept of relative speed and the formula for distance traveled: Distance = Speed × Time. Here's how you can solve it step by step:
1. Let's assume that the first train started traveling at time t=0. Therefore, when the second train started, t=2 hours.
2. Let's break down the information given:
- Speed of the first train (going west) = 70 km/h
- Speed of the second train (going east) = 90 km/h
- Distance at which they meet = 1420 km
3. Let's consider the time the first train traveled until they meet as t hours.
4. Now, we can calculate the distance traveled by each train using the formula Distance = Speed × Time:
- Distance traveled by the first train = 70t km
- Distance traveled by the second train = 90(t-2) km (since it started 2 hours later)
5. Since the total distance traveled is 1420 km, we can write the equation:
70t + 90(t-2) = 1420
6. Solve the equation:
70t + 90t - 180 = 1420
160t = 1600
t = 10
7. Substituting the value of t back into our equations, we can find:
- Distance traveled by the first train = 70t = 70 * 10 = 700 km
Therefore, the first train had traveled 700 km when the two trains were 1420 km apart.
Note: In step 6, when we combined like terms, we subtracted 180 from both sides to isolate the variables on one side of the equation.