Answer: (d)
Explanation:
Given
Mass of object 
Speed of object 
Mass of object at rest 
Suppose after collision, speed is v
conserving momentum

Initial kinetic energy

Final kinetic energy

So, it is clear there is decrease in kinetic energy . Thus, energy decreases and velocity becomes 2 m/s.
Answer:
The average angular acceleration is 
Explanation:
From the question we are told that
From the question we are told that
The length of the bat is
\
The initial linear velocity is 
The time is 
The velocity at t is 
Generally average angular acceleration is mathematically represented as

Where
is the finial angular velocity which is mathematically evaluated as



and
is the initial angular velocity which is zero since initial linear velocity is zero
So


Answer:
what is the question. . .
The period of the wave would be halved