What Is the Initial Velocity of the Green Car with Constant Acceleration?

[cynical555]

Homework Statement

Two cars, a red one(left side) and a green one(right side), are moving toward each other in adjacent lanes. At time t=0, the red car is at position x= 0 m and the green car is at position x= 220 m. If the the red car has a constant velocity of 20km/hr, it passes the green car at x= 44.5 m. If the red car has a constant velocity of 40 km/hr, it passes the green car at x= 76.6 m. What is the initial velocity of the green car assuming its acceleration to be constant?

Homework Equations

The Attempt at a Solution

i found that the green car has moved 175.5 m after 8 s and that the car moved 143.4 m after 6.89s.
thanks in advanced!

 

[caljuice]

Now that you got the time, find the equation for the distance traveled for both cases and equate them together. Initial velocity and acceleration are the same for both of them, so you can find what you need. I got around ~51 m/s, ignoring sig figs. Hope that's correct.

 

[supratim1]

two unknowns - initial velocity (u) and acceleration (a) of green car. you get two equations of motions, and two unknowns. so solve them to get the answer.

 

[supratim1]

and Welcome to Physics Forums cynical555!