Answer:
The force acting on the ball is 92.4 N.
Explanation:
Given that,
Initial speed of the ball, u = 0
Final speed of the ball, v = 31.6 m/s
The average power generated during the serve is 2920 W. Power generated by an object is given by :

W is the work done, W = Fd

Since, 
So,

F is the force acting on the ball

So, the force acting on the ball is 92.4 N. Hence, this is the required solution.
Answer:
The voltage drop across the bulb is 115 V
Explanation:
The voltage drop equation is given by:

Where:
ΔW is the total work done (4.6kJ)
Δq is the total charge
We need to use the definition of electric current to find Δq

Where:
I is the current (2 A)
Δt is the time (20 s)


Then, we can put this value of charge in the voltage equation.

Therefore, the voltage drop across the bulb is 115 V.
I hope it helps you!
Answer:
The turbine is rotated and rotates the generator to produce electricity.
Explanation:
Within a turbine enters the superheated steam which is at high pressure and high temperature, this steam is previously formed in the boiler when the steam enters the turbine hits each one of the blades of the turbine making it rotate at a given speed, the turbine shaft is coupled to the shaft of an electric generator and thus generates electricity.
It is also important to say that when the steam comes out of the turbine comes out at low pressure, this way the internal operating process is carried out within the turbine.
i don't know the anss , sorry.
Physical change = changes the physical properties (more commonly known as it's look)
Chemical change = changes the chemical properties into an entire new chemical form
Examples of physical change would be melting ice cubes or sugar cubes.
Examples of chemical change would be cooking eggs or burning paper because you're changing its chemical properties.