Newton's 2nd law of motion:
Force = (mass) x (acceleration)
Divide each side by (mass):
Acceleration = (force) / (mass)
= (100 N) / (50 kg)
= 2 m/s²
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
a) In this case the forces are the centrifugal force Fcp,
which is directed horizontally toward the wall; the force of static friction Ff
with the wall, directed upward; the normal force Fn by the wall, which is
directed away the wall; the force of gravity Fg, directed downwards. Then we
have that the horizontal forces are all equal in magnitude; similarly the
vertical forces are also all equal in magnitude.
b) The minimum coefficient s occurs when force of gravity
is equals the max friction force, that is
Fg = Ff,max
m g = s Fn
Also, the normal force has equal magnitude to the
centrifugal force:
m g = s Fcp
m g = s m w^2 r
g = s w^2 r
s = g / (r w^2)
With values: g = 9.81 m/s^2; r = 2.5 m; and w = 2pi *
0.60 = 3.77 rad/s; we find
s = 9.81 / (2.5 * 3.77^2) = 0.276
The answer is D, Carbon and hydrogen