Answer:
For the first situation, we first need to find the mass of the second train car.
In order to do that, we apply the conservation of the amount of movement:

and we have as a result:
m2 = 289.6875
For the second situation, also we will apply the conservation of the amount of movement:

and we have as a result:
V = 2.64 (it is moving to the right)
Answer:
this is because the light rays get reflected irregularly
Explanation:
Answer:
The answer to your question is 1.35 Watts
Explanation:
Data
Work = W = 5 J
time = t = 3.7 s
Power = P = ?
Formula
Power is a rate in which work is done or energy is transferred over time
P = 
Substitution

Result
P = 1.35 W
we know
T=2.pie sqr root(l/g)
l= (sqrof 7/22)*9.8
L= .99 or approx 1m