The average speed is the distance (a scalar quantity) per time ratio. Speed is ignorant of direction. On the other hand, velocity is a vector quantity; it is direction-aware. Velocity is the rate at which the position changes.
Fission. In a nuclear explosion the atom nucleus splits, not in a conventional explosion
Answer:
Part a)

Part b)

Explanation:
As we know that there is no external force on the system of two masses so here total momentum of the system will remains conserved
so we can say




Part b)
magnitude of the initial speed of A = 
magnitude of the initial speed of B = 
magnitude of final speed of A = 
magnitude of final speed of B = 
Now change in total kinetic energy is given as



The answer is Newton's 3rd Law. The reason why is because a force is a push or a pull that acts upon an object as a results of its interaction with another object. ... These two forces are called action and reaction forces and are the subject ofNewton's third law of motion. Formally stated, Newton's third law is: For every action, there is an equal and opposite reaction.
Answer:
The kinetic energy of the system after the collision is 9 J.
Explanation:
It is given that,
Mass of object 1, m₁ = 3 kg
Speed of object 1, v₁ = 2 m/s
Mass of object 2, m₂ = 6 kg
Speed of object 2, v₂ = -1 m/s (it is moving in left)
Since, the collision is elastic. The kinetic energy of the system before the collision is equal to the kinetic energy of the system after the collision. Let it is E. So,

E = 9 J
So, the kinetic energy of the system after the collision is 9 J. Hence, this is the required solution.