By putting to much weight on it our body causing it to hurt or fall hope this helps
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
The period of a simple pendulum is given by:

where L is the pendulum length, and g is the gravitational acceleration of the planet. Re-arranging the formula, we get:

(1)
We already know the length of the pendulum, L=1.38 m, however we need to find its period of oscillation.
We know it makes N=441 oscillations in t=1090 s, therefore its frequency is

And its period is the reciprocal of its frequency:

So now we can use eq.(1) to find the gravitational acceleration of the planet: