I think the correct answer would be that there are a relatively small number of moles of HCl present. Dilute would mean that there are very few solute particles dissolved as compared to the solvent particles in the solution. Hope this helps.
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:
In coin card experiment smooth card is used so that the card can slide easily from glass
The magnitude of electric field is produced by the electrons at a certain distance.
E = kQ/r²
where:
E = electric field produced
Q = charge
r = distance
k = Coulomb Law constant 9 x10^9<span> N. m</span>2<span> / C</span><span>2
Given are the following:
Q = </span><span>1.602 × 10^–19 C
</span><span>r = 38 x 10^-9 m
Substitue the given:
E = </span>
E = 998.476 kN/C
Tension is the force causing the path. It is always directed inward for circular motion. To hit the ceiling you need B. The stopper will travel along the tangent line it was moving when released (when tension goes to 0). This is upward in B so it will keep going up to the ceiling.
The velocity is pointed along the tangent line at all times (parallel to the edge of the circle at any point)