The correct answer is A. Charged particles from the sun exite the atmosphere near the poles to create auroras.
Answer:
We know there's two forces acting on a book while it sits on a table:the force of gravity pulling it down, and the normal force of the table acting upward on the book. The book isn't accelerating while it sits there. That's because the weight of the book is being counteracted by the normal force of the table.
Explanation:
There are two forces acting upon the book. One force - the Earth's gravitational pull - exerts a downward force. The other force - the push of the table on the book (sometimes referred to as a normal force) - pushes upward on the book.
Answer
given,
time = 10 s
ship's speed = 5 Km/h
F = m a
a is the acceleration and m is mass.
In the first case
F₁=m x a₁
where a₁ = difference in velocity / time
F₁ is constant acceleration is also a constant.
Δv₁ = 5 x 0.278
Δv₁ = 1.39 m/s

a₁ = 0.139 m/s²
F₂ =m x a₂
F₃ = F₂ + F₁
Δv₃ = 19 x 0.278
Δv₃ = 5.282 m/s
a₃=Δv₂ / t

a₃ = 0.5282 m²/s
m a₃=m a₁ + m a₂
a₃ = a₂ + a₁
0.5282 = a₂ + 0.139
a₂=0.3892 m²/s
F₂ = m x 0.3892...........(1)
F₁ = m x 0.139...............(2)
F₂/F₁
ratio = 
ratio = 2.8
The 'formulas' to use are just the definitions of 'power' and 'work':
Power = (work done) / (time to do the work)
and
Work = (force) x (distance) .
Combine these into one. Take the definition of 'Work', and write it in place of 'work' in the definition of power.
Power = (force x distance) / (time)
From the sheet, we know the power, the distance, and the time. So we can use this one formula to find the force.
Power = (force x distance) / (time)
Multiply each side by (time): (Power) x (time) = (force) x (distance)
Divide each side by (distance): Force = (power x time) / (distance).
Look how neat, clean, and simple that is !
Force = (13.3 watts) x (3 seconds) / (4 meters)
Force = (13.3 x 3 / 4) (watt-seconds / meter)
Force = 39.9/4 (joules/meter)
<em>Force = 9.975 Newtons</em>
Is that awesome or what !
I think it’s b... not sure tho sorry