Answer:
Approximately
for the train from Boston to NYC Penn Station.
Approximately
for the train from NYC Penn Station to Boston.
Explanation:
Convert minutes to hours:
.
.
Calculate average speed of each train:
.

Assume that it takes a time period of
for the trains to pass by each other after departure. Distance each train travelled would be:
.
.
Since the trains have just passed by each other, the sum of the two distances should be equal to the distance between the stations:
.
Rearrange and solve for
:
.
.
Distance each train travelled in
:
.
.
The initial kinetic energy of the cart is

(1)
where m is the mass of the cart and v its initial velocity.
Then, the cart hits the spring compressing it. The maximum compression occurs when the cart stops, and at that point the kinetic energy of the cart is zero, so all its initial kinetic energy has been converted into elastic potential energy of the spring:

where k is the spring constant and x is the spring compression.
For energy conservation, K=U. We can calculate U first: the compression of the spring is x=60 cm=0.60 m, while the spring constant is k=250 N/m, so

So, the initial kinetic energy of the cart is also 45 J, and from (1) we can find the value of the initial velocity:
<u>Answer:</u>
<em>Construction of a railroad route is a strenuous task and one has to face several obstacles.
</em>
<u>Explanation:</u>
Setting up the best possible plan for laying a rail route is a time-taking task. Several factors like economical nature of the plan, proper availability of building materials, minimum river crossings etc should be considered.
To build a railroad route the government has to get hold of the land through which the railroad route is planned. This is never an easy task. The people of the area have to be given adequate compensation and should be properly evacuated. The chances of people disapproving the plan are more.
B. because my sister said so