Hey, i feel kinda embarassed asking this because it looks so simple.

a mass of 300kg which is positioned 1000m above the ground is allowed to fall to the ground. what will be its velocity on impact?

Use the basic velocity formula. Initial velocity is zero; solve for final velocity. Your acceleration is gravity.

so i should use

v^2 = u^2 + 2as

(v- final and u- initial)??

i did

v^2= 0+ 2(9.81)(1000)
= 19620

and then i find the square root of that which is 140 m/s

is that correct?

Initial PE= final KE
mgh= 1/2 mv^2

V^2= 2gh= 2*1000*9.8
V= 140m/s