A ball is dropped , find the velocity after 100 m

Vf = 44.27 m/s

Explanation:

When a ball is dropped it is acted upon by gravitational force under free fall motion. So, in order to find its final speed we use 2rd equation of motion, as follows:

2gh = Vf² - Vi²

where,

g = acceleration due to gravity = 9.8 m/s²

h = height lost = 100 m

Vf = Final Velocity = ?

Vi = Initial velocity = 0 m/s (Since, ball starts from rest)

Therefore,

(2)(9.8 m/s²)(100 m) = Vf² - (0 m/s)²

Vf = √(1960 m²/s²)

Vf = 44.27 m/s

weight of the box is given as

here this is placed on the inclined of angle 42 degree

now this weight will have two components one is along the incline other is perpendicular to it

so here we need to apply a force parallel to incline opposite to its component of weight

so here the component of weight is given as

here we have

so it requires 75 n force to move it upwards

it is a negative acceleration