Answer:
Part a)

Part b)

Explanation:
Since the ball and rod is an isolated system and there is no external force on it so by momentum conservation we will have

here we also use angular momentum conservation
so we have

also we know that the collision is elastic collision so we have

so we have

also we know

also we know

so we have


now we have


Part b)
Now we know that speed of the ball after collision is given as

so it is given as

The work function is what we call the minimum energy that is required by an electron to leave the metal target in the photoelectric effect.
Answer:
option C
Explanation:
The correct answer is option C
Fire cut of fireman cut is diagonal cut which is provided at the end of the beam to prevent the fall of masonry wall if a fire breaks out in the building.
Fire cut allows joist to leave if it fails without affecting the masonry wall standing.
Without fire cut, the burnt beam will rotate downward affecting the connection of beam and wall and leading to damage it.
C stands for carbon. The O stands for oxygen. CO2 is one carbon atom and two oxygen atoms