Because the more advances made in the world means the more we can learn on how things work and how we can better the lives of humans and other species. If we didn't have scientific advancements we wouldn't have cell phones, electric, tv, car, computers, ect. We would still be living in Cave man era with clubs and horrible language skills.
Weight equals mass times gravitational acceleration=400N, so mass=400/9.8=41kg approx.
You told your insane friend that it will take the book 5.6 s to get to the ground.
From the question given above, the following data were obtained:
Height (H) = 155 m
<h3>Time (t) =? </h3>
<u>NOTE</u>: Acceleration due to gravity (g) = 10 m/s²
The time taken for the book to get to ground can be obtained as follow:
<h3>H = ½gt²</h3>
155 = ½ × 10 × t²
155 = 5 × t²
<h3>Divide both side by 5</h3>

t² = 31
<h3>Take the square root of both side </h3>

<h3>t = 5.6 s</h3>
Thus, the time taken for the book to get to the ground is 5.6 s
Hence, you told your insane friend that it will take the book 5.6 s to get to the ground.
Learn more: brainly.com/question/24903556