There are exactly three ways that could happen:
1). The container was heated, and the gas inside it got warmer.
2). Some part inside the container moved somehow, and made
the inside volume smaller, so the gas got scrunched into a
smaller space.
3). Somebody pumped some more gas into the container, so
a greater amount of gas had to live in the same space.
In order to compute the final velocity of the trains, we may apply the principle of conservation of momentum which is:
initial momentum = final momentum
m₁v₁ = m₂v₂
The final mass of the trains will be:
10,000 + 10,000 = 20,000 kg
Substituting the values into the equation:
10,000 * 3 = 20,000 * v
v = 1.5 m/s
The final velocity of the trains will be 1.5 m/s
Answer: a) speed = 3.45 × 10^-2 m/s
b) speed = 1.38 × 10^-1 m/s
Explanation: shown in the attachment
Weight = (mass) x (gravity)
= 200 Newtons.
(About 44 pounds. You're very skinny.)
