The question is looking for "ellipse" and "two" to fill in the blanks.
I would say the answer to your question is A Ferris wheel turning at a constant speed. The reasoning behind this answer is the fact that traveling in a constant direction at a constant speed is not accelerating. The Ferris wheel is the only option that fits this description. The last option would be incorrect due to independent causes such as speed limit changes as well as turns and stops on the highway.
Answer:
P = 7.28 N.s
Explanation:
given,
initial momentum of cue ball in x- direction,P₁ = 9 N.s
momentum of nine ball in x- direction, P₂ = 2 N.s
momentum in perpendicular direction i.e. y - direction,P'₂ = 2 N.s
momentum of the cue after collision = ?
using conservation of momentum
in x- direction
P₁ + p = x + P₂
p is the initial momentum of the nine balls which is equal to zero.
9 + 0 = x + 2
x = 7 N.s
momentum in x-direction.
equating along y-direction
P'₁ + p = y + P'₂
0 + 0 = y + 2
y = -2 N.s
the momentum of the cue ball after collision is equal to resultant of the momentum .


P = 7.28 N.s
the momentum of the cue ball after collision is equal to P = 7.28 N.s
Well a basic explanation is that some elements have enough electrons to be considered stable. These elements do not need to react with other elements to gain more electrons. Reactive elements are no where near stable; they respond with other elements in order to become stable. The more unstable, the harsher the reaction is.