Explanation:
It is given that,
Mass of the ball, m = 0.06 kg
Initial speed of the ball, u = 56 m/s
Final speed of the ball, v = -34.5 m/s (opposite direction)
(a) Let J is the impulse delivered to the ball by the racquet. It is equal to the change in momentum of the object as :


J = -5.43 kg-m/s
(b) The work done by the racquet on thee ball is equal to the change in kinetic energy as :


W = -58.372 Joules
Usually, sound needs a medium to travel through, like a vacuum for example.
Light does not need a medium to travel, and since air is considered a medium, light is not dependent on that.
On the other hand, sound needs a medium to travel through, and outer space doesn't contain space, therefore, no sound.
They belong to the kingdom of Chordata
I believe it is A. Electrons reside in known positions in fixed orbits around the nucleus
Eaither D or A bit I am leaning more towards D