Answer:
<h2>10,000 kg</h2>
Explanation:
The mass of the train can be found by using the formula

k is the kinetic energy
v is the velocity
From the question we have

We have the final answer as
<h3>10,000 kg</h3>
Hope this helps you
A) the tension in the string.
Answer:
Hiiiiiiii........where r u frm??
Answer:
Ive left an image here for use, I hope its helpful
Explanation:
I have left two images and i hope i am answering your question.