The net force = sum of all forces acting on the body
If we take left side as -ve and right side as +ve,
then,
The net force here would be equal to,
10N + (- 3N)
= 7N.
Therefore, a net force of +7N ( + indicates it's moving towards right) is acting on the book of mass 2kg.
Answer:
- a.

- b.

Explanation:
<h3>
a.</h3>
The equation for the voltage V of discharging capacitor in an RC circuit at time t is:

where
is the initial voltage, and
is the time constant.
For our problem, we know

and

So





This gives us

and this is the time constant.
<h3>
b.</h3>
At t = 18.8 s we got:



Since Arthur has developed a hypothesis and now is designing a study to test it, the answer which can provide the best guidance regarding his choice of measures, types of data to be collected, and methods for interpreting the data is the scientific literature in his area of interest.
Books and other research can help Arthur a lot when it comes to testing his hypothesis, because perhaps there have been other similar experiments that may aid him in putting his to the test.
I think it does matter because when the pillow is in contact to the cabin it is also at a velocity of 600 km/h, but as soon as it leaves the contact of the cabin, inertia tries to slow it down and the passenger being at 600 km/h has a risk of getting hit by it.