Posted by **Luicia** on Wednesday, October 3, 2012 at 7:14am.

A car leaves a city at 70 km/hr. After 15 minutes, another car follows at 80 km/h. How long will it take for the second car to reach the first, and at what distance?

- Physics -
**Jennifer**, Wednesday, October 3, 2012 at 10:14am
First, make sure all units are compatible:

Convert 15 minutes to hours, since the speeds are listed in km per hour.

15 minutes / 60 min/hr = .25 hours

Set up algebra equations:

Then let x be the distance traveled by the car that travels at 70 km/hr

Let y be the distance traveled by the car that travels at 80 km/hr

Let t be the time

When the second car starts, the first car has already traveled 70 km/h * .25 h = 17.5 km

x = 17.5 + 70*t

y = 80 * t

The cars will meet when x = y, or when

80*t = 17.5 + 70*t

Solve for t, the time at which they meet. Plug back t into the equation for x or y to find the distance at which they meet.

## Answer This Question

## Related Questions

- physics - 2 cars are in a race the first car is 200m ahead of the second car.the...
- Mathematics - A car X left town A for town B at the same time that another car Y...
- physics - Car A is travelling at 22.0 m/s and car B at 29.0 m/s. Car A is 300 m ...
- Physics - Car A is traveling at 18 m/s and car B at 25 m/s. Car A is 300m behind...
- Mathematics - The temperature, T (in ºF), of a car's radiator during the first ...
- Physics ***HELP*** - please explain how you got the answer car A - 20m/s car B...
- 11th grade Math - Two cars travel the same distance. The first car travels at a ...
- Physics - Both car A and car B leave school at the same time, traveling in the ...
- Physics - A car starts from rest and accelerates unifomly at 3m/s^2. A second ...
- Algebra - I don't understand how to find the equation to solve this. A family ...

More Related Questions