Given that,
Mass of trackler, m₁ = 100 kg
Speed of trackler, u₁ = 2.6 m/s
Mass of halfback, m₂ = 92 kg
Speed of halfback, u₂ = -5 m/s (direction is opposite)
To find,
Mutual speed immediately after the collision.
Solution,
The momentum of the system remains conserved in this case. Let v is the mutual speed after the collision. Using conservation of momentum as :

So, the mutual speed immediately after the collision is 1.04 m/s but in opposite direction.
This is the CBS's this is a B a bit
The kinetic energy with which the hammer strikes the ground
is exactly the potential energy it had at the height from which it fell.
Potential energy is (mass) x (gravity) x (height) .... directly proportional
to height.
Starting from double the height, it starts with double the potential
energy, and it reaches the bottom with double the kinetic energy.
2 times 10 to the power of 5 is your answer.