An egg test dummy is fitted with a helmet, sealed in a plastic bag and attached to a swing with a clamp. These items have a combined mass of 0.0900 kg. This mass is pulled back to a height of 0.550 m. The mass is then released and allowed to swing down and collide with a cement block. What is the speed (velocity) of the mass at the moment of impact? An 18000 kg freight train travelling at 1.75 m/s [E] collided with a 27000 kg freight train at rest. After the collision the freight trains stick together. What is the velocity of the freight trains after the collision?