what is the total linear momentum of the trolleys (before the spring is released)
Incomplete.
Constant
Remains constant
To determine the total linear momentum of the trolleys before the spring is released, you need to know the individual linear momenta of each trolley and then add them together.
The linear momentum of an object is defined as the product of its mass and velocity. So, to find the linear momentum of each trolley, you can multiply the mass of each trolley by its velocity.
Once you have the linear momenta of both trolleys, you can simply add them together to obtain the total linear momentum of the system.
In summary, the total linear momentum of the trolleys before the spring is released can be calculated by finding the individual linear momentum of each trolley and then adding them together.