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

can be answered using momentum.

momentum = p

p1= mass1 * velocity1

p1 = p2

therefore

p1 = 6kg * 4m/s

p1 = 24kgm/s

p2=m2 * v2

24 kgm/s = 7kg * v2

v2 = 24 kgm/s / 7kg

v2= 3.42 m/s