Ivan Pavlov was the researcher that first realized that certain psychic secretions pointed to a simple but important form of learning.
The way he figured this out was when dogs paired certain things with food, and because of this, the dogs started salivating.
Answer:
The magnitude of change in momentum of the ball is
and impulse is also
Explanation:
Given:
Velocity of a pitched ball

Velocity of ball after impact

From the formula of change in momentum,

Here mass is not given in question,
Mass of ball is 
Change in momentum is given by,


Magnitude of change in momentum is

And impulse is given by


So impulse and
Therefore, the magnitude of change in momentum of the ball is
and impulse is also