
Actually Welcome to the Concept of the Projectile Motion.
Since, here given that, vertical velocity= 50m/s
we know that u*sin(theta) = vertical velocity
so the time taken to reach the maximum height or the time of Ascent is equal to
T = Usin(theta) ÷ g, here g = 9.8 m/s^2
so we get as,
T = 50/9.8
T = 5.10 seconds
thus the time taken to reach max height is 5.10 seconds.
The number converted is 
Explanation:
In order to convert from the original units to the final units, we have to keep in mind the following conversion factors:



The original unit that we have is

Therefore, it can be rewritten as:

Therefore, since the initial number was 0.779, the final value is

#LearnwithBrainly
There are correlation and causation between the force of the finger and the movement of the books
F=ma
Tension - weight = mass x acceleration
T - 5(9.81) = 5 x 1
T = 5 + 5(9.81)
T = 54.05 N
T ≈ 54 N