Question

In the figure here, a red car and a green car move toward each other in adjacent lanes and parallel to an x axis. At time t = 0, the red car is at xr = 0 and the green car is at xg = 218 m. If the red car has a constant velocity of 21.0 km/h, the cars pass each other at x = 44.9 m. On the other hand, if the red car has a constant velocity of 42.0 km/h, they pass each other at x = 76.1 m. What are (a) the initial velocity and (b) the (constant) acceleration of the green car? Include the signs.

Answer 1

change meters to km, so we use km/hr throughout the problem

Answer 2

In the figure here, a red car and a green car move toward each other in adjacent lanes and parallel to an x axis. At time t = 0, the red car is at xr = 0 and the green car is at xg = 218 m. If the red car has a constant velocity of 21.0 km/h, the cars pass each other at x = 44.9 m. On the other hand, if the red car has a constant velocity of 42.0 km/h, they pass each other at x = 76.1 m. What are (a) the initial velocity and (b) the (constant) acceleration of the green car? Include the signs.

We have two kinematic (motion) equations
xg = 1/2*a*t^2 + vt + 218
xr = v*t

Answer 3

can you show me how to do it?

Answer 4

we use kinematic equations
for constant acceleration
x = 1/2*a*t^2 + v*t + xo ,
where
a = acceleration
v = initial velocity
xo = initial displacement from origin

for constant velocity
x = v*t + xo (since acceleration is zero)

Answer 5

for xg, we are told that x0 = 218 , and for xr , xo = 0