We want to find the combined volume of 3 tennis balls. We will get that the combined volume is 493.7 cm^3
First, remember that for a sphere of diameter D, the volume is:

Where 3.14 is pi.
Here we know that the average diameter of a tennis ball is 6.8cm, then we can replace that in the above equation to find the volume (in average) of a single tennis ball:

Now, in 3 balls of tennis, the combined volume will be 3 times the above one, this is:

If you want to learn more about volumes, you can read:
brainly.com/question/10171109
Answer:
A-Caclcuate the potential energy of the ball at that height
Explanation:
(a). Mass of the Body = 10 kg.
Height = 10 m.
Acceleration due to gravity = 9.8 m/s².
Using the Formula,Potential Energy = mgh
= 10 × 9.8 × 10 = 980 J.
(b). Now, By the law of the conservation of the Energy, Total amount of the energy of the system remains constant.
∴ Kinetic Energy before the body reaches the ground is equal to the Potential Energy at the height of 10 m.
∴ Kinetic Energy = 980 J.
(c). Kinetic Energy = 980 J.
Mass of the ball = 10 kg.
∵ K.E. = 1/2 × mv²
∴ 980 = 1/2 × 10 × v²
∴ v² = 980/5
⇒ v² = 196
∴ v = 14 m/s.
In the z-scheme, water is the initial electron donor and NADP+ is the final electron acceptor.
<u>Explanation:
</u>
It is a process of photosynthesis. It occurs in photosynthetic chemical reaction. The z scheme is basically a term for representing the oxidation and reduction reaction occurring in plants during photosynthesis.
The water present in the chlorophyll pigment donates electrons and become the initial electron donor. Those electrons get transferred to NADP+ and forms NADPH. Thus, water acts as electron donor initially and so the final electron is NADP+.
I believe the answer is 3). The cell wall provides protection, it doesn’t control movements of materials in and out of the cell.