Literally noone answers my questions please help Two trains leave towns 1490 kilometers apart at the same time and travel toward each other. One train travels 20 km/h slower than the other. If they meet in 5 hours, what is the rate of each train?

Answers:

Explanation:

x = rate of the slower train

x+20 = rate of the faster train

rates are in km per hour, abbreviated as kph

The train traveling at x kph will travel 5x km after 5 hours.

Use this formula

distance = rate*time

Using that same formula, the faster train travels 5(x+20) = 5x+100 kilometers in 5 hours.

The two distances must add to 1490 if we want the trains to pass by each other. Assume that the trains are traveling on parallel side-by-side tracks.

So,

(slower train distance) + (faster train distance) = 1490

(5x) + (5x+100) = 1490

10x+100 = 1490

10x = 1490-100

10x = 1390

x = 1390/10

x = 139

The slower train moves at a rate of 139 km per hour.

x+20 = 139+20 = 159

The faster train moves at a speed of 159 km per hour.

Check:

The slower train travels 139 kph and travels for 5 hours, so it covers a distance of 139*5 = 695 km

The faster train has a speed of 159 kph and travels for 5 hours, so it covers 159*5 = 795 km

Total distance = 695+795 = 1490

The answers are confirmed.

5

step-by-step explanation:

step-by-step explanation: a reaction is first order. if the initial reactant concentration is 0.0200 m, and 25.0 days later the concentration is 6.25 x 10-4 m, then its half-life is: