Answer:
an ellipse with the Sun at one focus or D
Explanation:
Answer for edgenuity
Answer:

Explanation:
consider the mass of each train car be m
m₁ = m₂ = m₃ = m
speed of the three identical train
u₁ = u₂ = u₃ = 1.8 m/s
m₄ = m u₄ = 4.5 m/s
m₅ = m u₅ = 0 (initial velocity )
final velocity
v₁ = v₂ = v₃ = v₄ = v₅ = v
using conservation of momentum
m₁u₁ + m₂u₂ + m₃u₃ + m₄u₄ + m₅u₅ = m₁v₁ + m₂v₂ + m₃v₃ + m₄v₄ + m₅v₅
m (1.8 + 1.8 + 1.8 +4.5) = 5 m v


Answer:
During those 3.00 seconds before stopping, the car travels a distance of 6 m.
Explanation:
The simple rule of three is a tool that is used to quickly solve problems, where three pieces of information must be known, and one of them operates as an unknown to be known.
Two magnitudes are directly proportional if one magnitude increases the other also does it, and if the magnitude decreases the other in the same way.
Being a, b and c known data and x the unknown, the value that we want to know, the rule of three when the magnitudes are directly proportional is applied as follows:
a ⇒ b
c ⇒ x
So: 
In this case, knowing that a truck travels at 2 m/s, the rule of three applies as follows: if in 1 second the truck travels 2 m, in 3 seconds how much distance does it travel?

distance= 6 m
<u><em>
During those 3.00 seconds before stopping, the car travels a distance of 6 m.</em></u>
As an object falls from rest, its gravitational energy is converted to kinetic energy
G.P.E = K.E = mgh
K.E = (80 Kg)(9.8 m/s²)(30 m)
K.E. = 23,520 J