Question

A ball of mass=2kg is dropped from h=100m. What is the final velocity when it reaches the ground? *

Answer 1

Answer:

45m/s

Explanation:

(here I'm taking gravity due to acceleration as 10 m/s^2 and not 9.8 m/s^2 to match the options)

We know that when an object is dropped from a certain height it has initial velocity 0 m/s

so;

u= 0m/s

s= 100m

a= 10m/s^2

Using 4th law of motion;

v^2 - u^2 = 2× a× s

v^2 - 0^2 = 2 × 10 × 100

v^2 = 2000

v = √2000

v = 44.72 m/ s

Final velocity = 45 m/ s (rounding off to 45)

Please feel free to tell me if you have any confusion.