Given:
The mass of the roll is m =0.4 kg.
The velocity of the roll is v = 7.2 m/s at a height h = 16.1 m.
To find the velocity when it strikes the opposition player, where height h'= 0 m
Step-by-step explanation:
According to the law of conservation of energy, the total energy is always conserved, so

Here, g = 9.8 m/s^2 is the acceleration due to gravity.
On substituting the values, the velocity will be

Final Answer: The velocity of the roll when it strikes the player is 19.17 m/s