The correct choice is D .
First, convert all the km/hr into m/s
You will get that
initial speed = 20 m/s
Initial speed of Green train = 40 m/s
Initial separation = 950 m
Velocity of approach = 20 - -40 = 60 m/s
relative acceleration = -4 m/s^2
v = u + at
0 = 60 - 4t
t = 15s
s = ut + 1/2 *at * t
s = 60 * 15 - 1/2 *4 * 225
s = 900 - 450
Separation when they stop = 450 m
hope this helps
Hypothesis: Enriched environments will have a positive effect and better performance of the experimental group of animals exposed to toys in comparison to the control group of animals in running in mazes.
Dependent Variable: Control Group
Independent Variable: Exposed/Experimental Group
