d = rt
Let's begin with an example:
A train leaves Deb's house and travels at 50 miles per hour. Two hours later, another train leaves from Deb's house on the track beside or parallel to the first train but it travels at 100 miles per hour. How far away from Deb's house will the faster train pass the other train?
Remember, d will represent the distance in miles from Deb's house and t will represent the time that the slower train has been travelling.
It is helpful to draw a diagram to show what is happening, see the Train Diagram image.
Organize the information you have in a chart if you haven't solved these types of problems before. Organize your chart by giving the equation information and the formula:
distance= speed x time
.See the image.
Now you can solve the system of equations:
50t = 100 (t - 2)
50t = 100t - 200
200 = 50t
t = 4
Now substitute t = 4 into train 1
Now you can write your statement. "The faster train will pass the slower train 200 miles from Deb's house.
Now try solving similar problems:
A train left Chicago and traveled towards Dallas. Five hours later another train left for Dallas traveling at 40 miles per hour with a goal or catching up with the first train bound for Dallas. The second traing finally caught up with the first train after traveling for three hours. How fast was the train that left first going?
Remember to use a diagram to arrange your information. Then write the 2 equations to solve your problem.
One train left the station and traveled toward its destination at a speed of 65 miles per hour. Later, another train left the station traveling in the opposite direction of the first train, it was going at a speed of 75 miles per hour. After the first train had traveled for 14 hours it was 1960 miles apart from the second train. How long did the second train travel?
Remember to use the formula that supports what you're looking for - distance? speed/rate? time?
d = rt (Multiply)
r = d/t (Divide)
t = d/r (Divide)