Answer:
- Particles smaller than atoms are called subatomic particles .
- There are three famous subatomic particles, proton, neutron and electron .
- The study of sub atomic particles are called particle physics
- These particles can be divided as Brayons and Leptons
- These particles are often held together by one of the four fundamental particles ( Weak force, strong force, electromagnetic force, gravitational force).
As its charge, proton -a positive charged molecule at the center of an atom- is the opposite of the electron -the particle which is orbiting the center of an atom.
Accelerated motion such as a vehicle (car) or a moving item such as a (football thrown in the air)
Answer:

Explanation:
Given data:
Momentum of moving model train, 
Mass of the stationary model train, 
Initial speed of the stationary model train, 
Assume there is no external force is acting on the given train system.
In this case, the total linear momentum of the trains would be conserved.
Let the final linear momentum of the trains be 
Thus,




