Atrain moves forward at a constant speed. what is true about the forces
acting on the train? sc. c.2.3.6
a. the forward forces are equal to the forces acting in the backward
direction.
b. the forward forces are greater than the forces acting in the backward
direction.
c. the forward forces are smaller than the forces acting in the backward
direction.
d. there can never be any force acting on the train when it moves at a
constant speed.

An object moves at a constant speed if the net force acting on it is zero.

So, the correct answer is A: forwards and backwards forces cancel each other, and the train moves with constant speed.

vapour or gas assuming atmospheriv pressure

d₁ = displacement of tern from arctic to antarctic = 11000 miles

d₂ = displacement of tern from antarctic to arctic =   - 11000 miles

d = total displacement for the journey

total displacement for the journey is given as

d = d₁ + d₂

d = 11000 + (-11000)

d = 0 miles

t₁ = time of travel from arctic to antarctic = 3 months = 3 x 30 days = 90 days

t₂ = time of travel from antarctic to arctic = 3 months = 3 x 30 days = 90 days

t = total time of travel

total time of travel is given as

t = t₁ + t₂

t = 90 + 90

t = 180 days

average velocity is given as

average velocity = total displacement/ total time

v = d/t

v = 0/180

v = 0 miles/day