What is the variable?
~<em>the</em><em> </em><em>price</em><em> </em><em>is</em><em> </em><em>the</em><em> </em><em>variable</em><em>.</em>
What happens to demand?
~It'll go down. Since the price of snow blowers will increase then the quantity demanded will go down.
Hope this helps- have a good day bro cya)
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


Vocabulary should be, I think:
I. Hypothesis
II. Evidence, data
III. Experiment
What is your question exactly?